MTN is ****. *****ing money

Been trying to cancel my contract as my contract is up. No one is cancelling it and I am being debited the full contract amount for a contract that has ended and has been cancelled. Now debit orders have bounced and who is left to pay the bank fees? Won't refund me. Keep transferring me to each and everyone in the whole of mtn. Can't seem to speak to anyone who will resolve it. Won't escalate it. Nothing gets done regardless of all the proof I have sent through.