Disappearing airtime – MyBroadband 2018 test

Smartphone users regularly complain that their airtime or data is disappearing for unknown reasons.
This phenomenon, however, can usually be attributed to background application downloads, malware, or WASP services.
Airtime can really disappear, as experienced by Vodacom and MTN customers last year, but this is very rare and are often once-off cases.
In 2017, Vodacom subscribers were shocked when their airtime and data disappeared, and continued to do so after attempts to recharge.
Vodacom said the billing issue was due to a bug, and reimbursed customers.
Just before this, MyBroadband discovered that MTN airtime was slowly disappearing during a SIM test.
MTN said the issue was due to LTE connection charges, and adjusted its systems to solve the problem.
Due to these events, we decided to conduct a new round of “disappearing airtime” tests for the start of 2018.
A new SIM from each major network was purchased, loaded with airtime, and placed in an LTE-enabled smartphone – as detailed below.
The Tests
Each prepaid SIM was loaded with R10.00 airtime and placed in a Nokia 5.
The tests consisted of the smartphones being set up in four configurations for set periods of time.
The configurations, with the SIM in and airtime loaded, were:
- Smartphones off.
- Smartphones on and Wi-Fi on.
- Smartphones on, Wi-Fi off, and mobile data on.
- Smartphones on, Wi-Fi and mobile data off.
An airtime balance reduction was expected during the third test, and the balances were topped up when necessary before the next stage of testing.
The prepaid SIM cards began with the following balances:
- Vodacom – R10.00
- MTN – R10.00
- Telkom – R10.00
- Cell C – R10.00
All devices were using clean installs of Android and had exactly the same applications installed and settings enabled.
The results for each stage of the test are below.
Devices Off
The airtime balances on the devices remained constant after they were left off for an extended amount of time.
- Vodacom – R10.00
- MTN – R10.00
- Telkom – R10.00
- Cell C – R10.00
Wi-Fi On
No noticeable “disappearing airtime” was observed after Wi-Fi was enabled and the devices were left on.
- Vodacom – R10.00
- MTN – R10.00
- Telkom – R10.00
- Cell C – R10.00
Mobile Data On
By switching Wi-Fi off and enabling mobile data, the airtime balance would be slowly depleted by default services and applications.
Subsequently, we used the My Data Manager app to track the data usage on the devices for this test.
By comparing the data used and the amount of airtime depleted, we could point out any irregularities.
There were no major discrepancies between the amount of data used and the depleted airtime balance, except for the Telkom airtime balance – which remained unaffected despite mobile data usage.
No promotional data was applied to the Telkom SIM at the time of this test.
- Vodacom – R0.99 (9.04MB used)
- MTN – R0.00 (6.89MB used)
- Telkom – R10.00 (6.67MB used)
- Cell C – R1.53 (4.33MB used)
Connections Off
The prepaid SIMs were each reloaded with R10.00 airtime and both mobile data and Wi-Fi were turned off.
We measured no change in the airtime balances during this test.
- Vodacom – R10.99
- MTN – R10.00
- Telkom – R10.00
- Cell C – R11.53
Verdict
Our tests show that there were no instances of “disappearing airtime” on our devices.
What did stand out, however, is the out-of-bundle (OOB) rates the networks charged on prepaid SIMs which were left on their default plans.
Consumers are advised to examine their OOB rates regularly, particularly if they move to a new price plan or contract.
It must also be noted that the data usage on our devices during the mobile data stage of the test mainly consisted of Google Services Framework and OS Services.