Fed up!!!!

I am now sick and tired of having to deal with a company whose service is nothing but disgraceful. As far back as July, I phoned, e-mailed to change my banking details. For July and August, they persisted in debited my old banking details which of course resulted in the debit order not going through. All they did was blame the Bank. It does not take much intelligence to know that, yes, the Bank will reject if MTN continue to use old banking details. For goodness sake. I phoned again and again and it was only after many exhaustive calls that I got through to a call agent who only then informed me that I would need to go to an MTN to change my banking details as the call centre agents were not allowed to do this. For goodness sake why was I not informed at the beginning of the saga???????? I then had to go to an MTN store and pay my outstanding 2 months' payments. I also changed my banking details with them. I checked on my balance and saw that I had an amount outstanding and phoned the call centre yesterday (1st Nov) to query why no payment had gone through my account. I was informed not to worry it will still probably go through that day. I phoned again today ( ********** 42) and lo and behold was informed that the payment was rejected???? Oh my word, what can one say? I cannot believe this, but once again, my payment went through the old banking details which has obviously not been paid. What do I have to do to get you to use my new banking details which I have been giving to you since July? Is it my fault that your inefficient staff did not give me the correct procedure to follow in the first place and yet again even going to an MTN store to have my new banking details loaded on your pathetic systems has not helped. Furthermore I have not even received any sms's to say that my debit order did not go through. I am trying to pay what is due to MTN. MTN, what do I have to do now? Is there anyone out there who is understanding my problem and who is willing and able to sort it out? I have another 4 months to sit through this contract and its then its good riddance to MTN and their utter lack of anything resembling a service to customers. All I can say now is that this MUST NOW be sorted out once and for all. I am trying my utter best to pay my account but if MTN continue to not abide by my instructions of debiting my new banking details, I will have no choice but to take this matter further.