Disappearing airtime in 2020 – Unexpected background charges

Tests conducted by MyBroadband have shown that airtime balances on new Cell C and MTN prepaid SIMs are being depleted.
South African mobile users often complain about “disappearing airtime”, and we regularly conduct tests to determine whether airtime is truly depleting on its own.
In July 2017, MyBroadband discovered that MTN airtime was depleting with no clear reason, even when mobile data was switched off on the test device.
MTN subsequently addressed the problem, which it said was due to out-of-bundle data usage and the need for devices to establish an LTE network connection even when not using mobile data.
In the case of our first test in 2020, both MTN and Cell C airtime balances were decreasing due to out-of-bundle data being enabled by default. However, this usage was disproportional relative to other operators.
The test, which was conducted across Vodacom, MTN, Cell C, and Telkom SIMs, is detailed below.
The test
To see if irregular airtime depletion was occurring on mobile networks, MyBroadband placed new prepaid SIMs into four Samsung Galaxy S7 Edge smartphones.
The smartphones were connected to the same active Wi-Fi connection with the same applications installed, and each was registered to the same Google account.
We also checked if any of the SIMs were subscribed to WASP services via USSD menus. All the SIMs reported they were clean.
Each SIM was then was loaded with R10 airtime at the start of the test.
All settings were left on their default configurations to simulate a real-world user scenario.
On 27 February 2020, the prepaid SIMs reflected the following airtime balances:
- Vodacom – R10.00
- MTN – R10.00
- Telkom – R10.00
- Cell C – R10.00
No user actions which would have consumed airtime or data were performed. The smartphones remained powered on and connected to a stable Wi-Fi connection for the duration of the test.
Airtime balances were recorded regularly and mobile data usage was monitored through the My Data Manager app for Android.
It should be noted that the MTN SIM was credited with 250MB of WhatsApp data when we recharged it with airtime – this balance was noted and monitored.
Wi-Fi On – Vodacom 5c difference
After leaving all the smartphones powered on and connected to Wi-Fi for three days, we checked the airtime balances again.
We noted that three smartphones had a data balance of R10.00, except for Vodacom – which had a data balance of R9.95.
This difference was curious, but the Vodacom airtime balance did not decrease any further throughout the test.
As of 2 March 2020, the prepaid SIMs reflected the following airtime balances:
- Vodacom – R9.95
- MTN – R10.00
- Telkom – R10.00
- Cell C – R10.00
At this stage, we turned off the Wi-Fi connections of the smartphones and left their mobile data connections active.
None of the SIMs had an active data balance, except for the MTN SIM, which had a WhatsApp data balance of 250MB.
Wi-Fi Off – Cell C and MTN depletion
We left the smartphones with no Wi-Fi connection for two days before checking their airtime balances again.
The Telkom SIM still had a balance of R10.00 and the Vodacom SIM had retained its R9.95 balance. The MTN and Cell C SIMs, however, were short.
With airtime balances of R6.39 and R6.94 respectively, the MTN and Cell C SIMs had lost over R3 each in two days.
The My Data Manager showed similar mobile data usage across all devices – mostly trace amounts of data for Google Play Services.
On 4 March 2020, the prepaid SIMs reflected the following airtime balances:
- Vodacom – R9.95
- MTN – R6.39
- Telkom – R10.00
- Cell C – R6.94
ICASA’s End-User Service and Subscriber Charter requires that out-of-bundle mobile data usage be an opt-in service in South Africa, but networks can choose to only disable out-of-bundle data depletion once a bundle has been purchased and depleted.
In addition to this, the WhatsApp data balance on the MTN SIM did not decline. The Vodacom and Telkom SIMs were also left on their default settings and did not suffer airtime depletion.
As the data usage across all SIMs was similar, it means that even if we were charged for out-of-bundle data on the MTN and Cell C SIMs, Vodacom and Telkom allowed the same levels of trace background data usage without depleting our airtime balance.
Inconsistent airtime depletion
The depletion of airtime relative to background data usage was therefore not consistent across the operators.
For example, the device with the Telkom SIM showed 7.3MB of data usage over the two days and no airtime was lost. The Cell C SIM, however, showed 4.8MB of data usage and its airtime balance fell by R3.06.
The MTN device showed 9MB of background data usage and lost R3.61 of its airtime balance, while the Vodacom SIM showed 3MB of data usage and did not fall past R9.95.
These results are summarised below:
SIM | Background data usage | Airtime depleted |
---|---|---|
Vodacom | 3MB | R0.00 |
Telkom | 7.3MB | R0.00 |
Cell C | 4.8MB | R3.06 |
MTN | 9MB | R3.61 |
It is also important to note that neither the MTN or the Cell C SIM received any notification SMSs warning of out-of-bundle data depletion or declining airtime balances.
Trace background usage (mostly attributed to Google Play Services) occurs even when out-of-bundle data usage is disabled, as in the case of the Telkom SIM.
MTN responds
MTN said it noted results of the test, adding that the depleted airtime was due to out-of-bundle data usage being enabled by default on MTN prepaid SIMs.
“Upon our investigation, we have found that MyBroadband conducted the test with a new MTN SIM card, and all new prepaid customers on MTN are charged an out of bundle rate of R0.29c/MB until they have purchased a data bundle, or if they change their OOB data settings using our self-service channels,” MTN said.
“A new MTN SIM card with a recharge of R10 or more is provisioned with free 250MB for WhatsApp, free 1GB for the Ayoba messaging app, and free 60 night minutes as a part of the MTN Bundle bonanza promotion,” it added.
“The charges incurred on the tested MTN SIM card were background traffic (Google, YouTube, and Samsung) on the phone which was charged from the expiry airtime wallet.”
MTN said this background usage, and out-of-bundle data usage being enabled by default on prepaid SIMs, resulted in the airtime depletion recorded in the test.
The company did not respond when asked why the smartphones with Vodacom and Telkom SIMs did not show airtime depletion despite their background mobile data usage being similar to the MTN device.
Vodacom responds
Vodacom noted that as a data bundle had not been purchased and depleted on the Vodacom SIM, out-of-bundle data usage would be applied.
“Our OOB block implementation is in line with the ICASA regulations,” Vodacom said. “The regulation states that no OOB charges are to be applied by default once a data bundle is depleted.”
“If this is a new prepaid SIM which attempts to use data without the purchase of a data bundle, OOB usage will be applied. We stop applying OOB by default after the depletion of an active data bundle.”
Interestingly, however, Vodacom did not charge our SIM for the trace background data used for Google Play Services, despite stating that out-of-bundle data usage was enabled.
Cell C responds
Cell C noted that its out-of-bundle data charges were enabled by default, and stated this would account for the airtime depletion.
“Based on the End User Services and Subscriber Charter Regulations, all customers activated on a new SIM card will receive an SMS asking whether they would like to opt-out of OOB usage,” Cell C said.
This message reads: “As per law, you can select to continue using data at out-of-bundle rates or to stop data usage when your bundle depletes. Choose now, dial *147# option 2. If no choice is made data usage will continue.”
Cell C said that applications running in the background would consume airtime if no choice was made.
Telkom – No OOB billing
The airtime balance on the Telkom SIM did not change throughout the test, as Telkom automatically blocks out-of-bundle billing for prepaid customers by default.
When Telkom customers try to access the Internet and their data is depleted, they are presented with a web page informing them they must purchase a data bundle to continue browsing.