We tested for disappearing data in South Africa — and one operator is guilty

Testing by MyBroadband revealed disappearing data on Cell C, even when we switched off mobile data and stopped using the phone.
MyBroadband conducted disappearing airtime and data tests in November on Vodacom, MTN, and Cell C.
We used three identical Huawei Mate 20 Pro devices to ensure an equivalent testing environment for all operators. All three devices were updated, and factory reset.
My Data Manager was installed to have a second opinion on data used during the test.
All updates were disabled, and all the apps were individually denied mobile network access.
Mobile data was switched off, and the phones were connected to a stable Wi-Fi internet connection for the duration of the test. VoLTE and data roaming were also switched off.
We used SIM cards that have been active for some time with varying levels of airtime and data.
All the SIM cards were checked to ensure that no WASP services were enabled that could use airtime or data.
The phones were kept in the same office for the duration of the test, and only USSD balance checks were performed to check data and airtime.
During the week-long test, none of the devices showed mobile data use in the built-in Android settings or the My Data Manager app.
Checking the data balance on Vodacom and MTN confirmed that no mobile data was used. Cell C was, however, a different story.
Cell C showed that small amounts of data disappeared throughout the test.
The research further showed that no airtime was lost on any of the mobile operators during the testing period.
MyBroadband asked Cell C for comment about the disappearing data, and Cell C chief technology officer Schalk Visser said they recorded valid chargeable usage on their data network for our test device
Visser said that data could be consumed for various reasons, including 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,” Cell C has stated.
Testing summary
The table below provides an overview of the disappearing airtime and data testing results.
Disappearing Data and Airtime | |||||||
---|---|---|---|---|---|---|---|
Network | 10/11/2021 | 11/11/2021 | 15/11/2021 | 16/11/2021 | 17/11/2021 | 18/11/2021 | Difference |
Vodacom | R18.59 | R18.59 | R18.59 | R18.59 | R18.59 | R18.59 | R0.00 |
200 MB | 200 MB | 200 MB | 200 MB | 200 MB | 200 MB | 0 MB | |
MTN | R12.00 | R12.00 | R12.00 | R12.00 | R12.00 | R12.00 | R0.00 |
600 MB* | 899.9 MB* | 899.9 MB* | 899.9 MB* | 600 MB* | 100MB* | 0 MB | |
Cell C | R0.12 | R0.12 | R0.12 | R0.12 | R0.12 | R0.12 | R0.00 |
204767.43 MB | 204767.33 MB | 204767.14 MB | 204767.09 MB | 204767.04 MB | 204767.02 MB | 0.41 MB | |
*We bought a 100MB MTN data bundle and received an additional 500MB with a short expiry. Later, an additional 299.90MB was received. These additional data bundles both expired before the end of the test, and the 100MB was untouched. |
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