According to MTN SA, "We can confirm that the depletion was due to internet data traffic being channelled directly to the handset via LTE technology. LTE is an always connected technology, and as a result of LTE standards any compatible device connecting to the LTE network receives an IP address."So basically, if your device is LTE compatible, then the network will run off your device. You may not even be aware of this until you notice that your data has disappeared.
"These charges only occur when an LTE device, containing an LTE SIM card is in an LTE coverage area. This affects less than 3% of our customer base and does not occur during any 3G or Edge data sessions," explains MTN SA. Read More about the best data deal in South Africa below
"As a matter of priority, we are going to adjust our tariffs and align our data charging in LTE with our competitors. This will be implemented within the next 30 days."This is all good and well, however there has been no mention of remunerating their customers who lost data due to this problem.