Annoyed customer

Good day

I have been battling with the cancellation of my contract that ended in September 2022 and I phoned them in October 2022, but MTN has not cancelled it I have been told about the system error and that they can't cancel the contract, they are sending me from pillar to post. They are busy giving me reference numbers every time I phone in, and promising me that it will be cancelled, boom...come end of the month they still debit my money...MTN this is so frustrating, your system error is now your client's problem