MTN makes it nearly impossible to cancel the contract.

My wife had a contract which terminated in Dec 2020. An MTN sales rep rang her in Oct and she told the rep she did not want to renew the contract, However MTN ignored this and debited my wife in Jan 2021 for airtime. We reviewed the MTN website and found you can only call to cancel on the customer service 808 number. Despite calling this number many times and waiting literally hours she could not talk to anyone. Also tried the new number 135 same result! Today another sales person Baneshree called to offer another contract upgrade , My wife informed her that she was having a problem as MTN had ignored her request to cancel - of course Baneshree conveniently REFUSED to help as MTN is only interested in debiting money as it pleases. As we are emigrating she now will instruct her bank to cancel the debit order as ALL other means of communicating with this (communications ???) company has failed.