MTN have billed us R8000+ for data we did not use!

We have an MTN sim in a mini IPAD - on contract. The IPAD has been off for over 8 months. In November MTN debited R8000+ from our bank account. I reversed the debit order and contacted MTN. After holding for 30min we were told that it was for data usage. At which stage i said please can we log a ***** call as we didn't use the data. <br> December the same thing happened - amount debited and reversed. We contacted them again and i got through to a lady who changed account to cash account and said it was now logged with ***** (it had not been logged before) and that i would be contacted within 5 working days. No contact.<br> My husband in the interim tried calling to get feedback during January in excess of 4 times all the time - NO reference numbers were provided to us. We also requested to close the account. This was not done<br> New bill arrived in February. Contacted again yesterday - we spent almost 2 hours on the call. We were informed that ***** said it was not *****elent and our account has been handed over to legal - at no point has ANYBODY contacted us. We have request frequently that we get a report of what the data usage was used for etc - CAN ANYONE HELP!!!!