Not complying to contract

I have an account with MTN on which there is two contracts. One is a data contract and the other a mobile phone contract. In May MTN suddenly stopped my services, stated that I exceeded my data limit After further investigation, it appeared that a cost of R3097.53 went through on my account instead of the monthly agreement of R99. 00 (on the data contract). After further inquiries it was suggested to me that I downloaded 500MB every five minutes on the 20/5/2015 during the timeframe of 17:29 to 18:04. Sir, my computer is not even capable of downloading so much data in such a short time. If you check my records during the years I was a client at MTN, you will notice that I rarely if ever use up my data, since I have a Telkom Router and just use my MTN data for my bank statements and e-mails.<br> <br> I stopped my debit order and hence pay the correct account per contract and invoice number via internet banking each month, but my cellphone contract as well as the data contract are now virtually being cut off every week. I must organize that the cellphone (which is not at fault, but on the account) be enabled every week. It is very inconvenient for me since the phone is bein