Contract cancelation

I have been trying to cancel my contract MTN go months now I first went to Mtn in wondepark to cancel my contract but was told to call 135 or Send and email to retentions/accounts department I've been sending for over 3 months now but no joy. I've tried phoning 135 on 8 may call ref *** and they gave me an amount for cancelation then gave me wrong account details to pay the cancelation amount I then send an email to retentions with this matter and asked them to rather debit the amount to date they have not responded noh cancelled my contract. I need Mtn to cancel this contract I need Mtn to debit their cancelation amount and stop bebiting me after that.