Data disappears

I have 2 Data contracts ( 10 Gig and 5 Gig ) and 1 cell phone contract with Telkom. I use the data contracts as i work from home and every month i run out of data before the month is over. Then i need to spend more money on buying data or hotspotting from my phone.

This month the 10 Gig data was being used from 03/12/2018 and to date at 07/12/2018 the remaining data is 1.4 Gigs. I called and was told that that over 6 Gigs was used on 06/12/2018 from 8:30 to 18:43 and there is no way to trace it. I have not been downloading or updating any apps during this time and they cannot give me an valid reason as to why so much data has been used. On average for work i use more or less 1 Gig and for over 6 gigs to be used is really unreasonable. I cannot wait for the contract to be over.

Telkom is really terrible, even when calling into the call centre it takes over 12 to 20 minutes before the call can be answered.