MTN - Customer Service is friendly but not helpful at all.

MTN is starting to fall through the cracks. I upgraded my cellphone device and was told that I need to register for a debit order. I promptly paid my account every month via EFT and everybody was happy. The lady that assisted me, Thato from MTN Randridge Mall in Randburg, told me that we can cancel the debit order after the upgrade was made. I phoned MTN the following week and was told they can only cancel the debit order a month after the upgrade. I waited patiently and tried to cancel it again after a month only to be told that a debit order is now compulsory. The reason I don't want a debit order is that some years ago wrong amounts were charged against my bank account and to get that sorted was a nightmare. Subsequently I tried to change the banking details for the debit order only to be told, via email, "Early termination changes are app**** if customer requests for contract to be terminated prior end term". Eish! Nobody said anything about cancelling my contracts, or Early Termination!? I really don't understand. MTN insist on debit orders but cannot change the banking details. Please can someone explain this to me.