Millions worth of data disappearing from two operators in South Africa

Disappearing data and airtime tests by MyBroadband revealed that data worth millions of rands disappear from Vodacom and Cell C subscribers each month.

The test was conducted using four identical Nokia 5 devices with a prepaid SIM from each big mobile operator — Vodacom, MTN, Cell C, and Telkom.

The phones were set up to prevent mobile data use and connected to a stable Wi-Fi internet connection.

We also ensured that no WASP services were active on any SIM as this could consume airtime or data.

Data and airtime were loaded onto these SIMs, and the balance was checked over two weeks with USSD codes.

Previous tests revealed that small amounts of data disappeared from Vodacom and Cell C SIMs without any data use indicated by the devices.

The latest tests, conducted in June 2022, produced the same results.

The airtime and data balances on MTN and Telkom remained unchanged during the testing period, but Vodacom and Cell C lost 0.19MB and 1.07MB of data, respectively.

It is a small amount of data, but if it is consistent across all their subscribers, it will equate to millions of rands worth of data per month.

Vodacom and Cell C have approximately 21,700,000 and 5,700,000 mobile data subscribers, respectively.

An out-of-bundle data rate of R0.29 per MB equals data worth around R2.4 million being lost from Vodacom subscribers and more than R3.5 million from Cell C every month.

Disappearing data test

Why data disappears on Vodacom and Cell C

Cell C chief technology officer Schalk Visser has previously explained that Android smartphones may use mobile data while connected to an LTE network even when the connection is disabled.

“Under the 3GPP LTE standards, data traffic is possible across the 4G mobile network even when the ‘mobile data’ setting is turned off,” Visser said.

Vodacom explained the disappearing data happens because Android smartphones can use 4G mobile data even when the ‘mobile data’ setting is turned off.

“This is a function of how 4G is designed, the device, operating system, and relevant application developers,” a Vodacom spokesperson said.

“Testing has shown that small amounts of data are typically used for a connectivity test message in this way.”

Most applications will allow the handset settings to determine the bearer to be used, although app developers can force data over the mobile connection.

The second reason, Vodacom said, relates to the default billing rules on a new prepaid SIM.

Vodacom allows the SIM to go out-of-bundle using any airtime balance until the subscriber activates Data Limit Lock (DLL).

Only when DLL is opted into or if a bundle is purchased — DLL will be set by default when the bundle is depleted — will out-of-bundle charges be stopped.

“We encourage customers to change their Data Limit Lock (DLL) to R0 as soon as they purchase a new prepaid SIM,” Vodacom said.

Disappearing data test results

Now read: Vodacom disappearing airtime — what to look out for