MTN cancellations are impossible!!

I have been trying to terminate a contract with MTN for over a month. I was advised you need to contact Customer Care by phone. I tried this but there is only one option available to speak to a consultant which is under billing queries. Here it tells you to dial "0" to speak to a consultant. On dealing "0" it tells you "you have made an invalid selection". I managed to get an email from them dated 2 August stating my number was scheduled for cancellation on 26 August. However they have again debited me for a full month out of contract fee and now told me mu number has been migrated to pre-paid. It is so frustrating as they keep charging me horrific monthly charges and dragging on the process of cancelling. The service is so poor.