They just can not cancel or stop my account

I have phoned the MTN head office number that was given to me, was said they cannot cancel an account over the phone, I would have to go in to an MTN shop. I do as I was told and head to the nearest MTN shop. Again I get a order that the shop cannot do this I have to go the the head office in Cape Road, Newton Park, Port Elizabeth. I was assisted here and was told the account would be cancelled the coming month. This whole process took the entire day. Two months later and my account is still being debited. I phone again to ask what is going on? and was told to go into the head office... I am also working for a large corporate company as their IT admin, we have cancelled almost in total 50 mtn contracts because of this type of service. It is not allot to ask and I think a simple task, I have been trying to cancel this account for almost 3 months now with the contract being 5 months out of contract already. What can I do here? Does it count as *****ing now? I don't know what to do anymore. I need the money, as I am having financial issues, this is the reason for me cancelling the account.