MTN

My husband had a Data Contract with MTN which was from 03.08.2018 to 02.08.2020 which has now expired. We tried to cancel this contract but MTN refuse to do so. It came to the point where we have changed our bank account to stop the debit order. Now they have cancelled my cell in that I can no longer use to make or receive calls. 6 calls later and they still will not cancel. I have all the documentation should you require it. As my husband is a pensioner, we need help as we are being totally exploited and abused by this concern.