Cancellation of expired contract

I am appalled by the lack of service I have received from MTN. My data contact expired in Jan 2022 and I requested it to be cancelled in Feb 2022. MTN however has continued to incorrectly debit my account every month. I have phoned MTN multiple times and requested the cancellation over and over again, with no result. I have also visited a branch twice. I have never received worst customer service in my life. You are able to take out a contract or upgrade easily however when that contract expires MTN is useless. I will never consider taking out another contract with them. Absolutely shocking service!