Non existing customer service

I have two unresolved queries with MTN. I've tried logging queries on their website and also went to a local branch but still I get no feedback: Acc no: A***<br> 1) I had a data contract for which I received an out of bundle data charge of R1600 for usage of 0MB. Looking at my on line balance statement at the time, I had 2 GB of data carried over from previous months and 887 MB from the current month, so no one could explain why I'm being charged for out of bundle data. Looking back in history, I found that this has been ongoing for the past year, only in smaller amounts - R12 - R340 per month for MTN Live, but each invoice had 0MB usage. Until I received the R1600 extra on my bill, I did not pick it up in the combined d/order with the other two contracts I have with MTN. After a long fight, I managed to convert this contract that is already >24 months old to Pre-paid, but the unexplained data charges remain.<br> 2) I also had a cellphone contract that expired on 12 May 2015. During the previous month, more than R500 airtime disappeared also on data charges that cannot be explained to me. I registered a query to move this contract to Pre-paid but it was not done. No answer on 808