ANGRY AS HELL - MTN DONT LISTEN

I cancelled my MTN account last year August. I was told that I had to pay a cancellation fee which I did. MTN Continue to debit my account every month. I have to go to the bank every month and tell them to reverse this charge. (I missed OCtober reversal so they still owe me this) but none the less - what will it take to cancel my account with MTN! I have email correspondence to and from MTN - I have proof of cancellation payment, they keep putting this off - the number that was cancelled isn't even in use anymore so they cancelled the number yet continue to debit my account each month!