What to do with this place

I will never advise anyone to use mtn in fact I would beg people around me to save themselves the trouble of using MTN as they only care about making the costumer commit. Thereafter they have no interest in assisting customers. No one can ever give you any answers or knows what is what. I have been struggling with MTN since the first month I got the contract I have settled the payments yet I keep getting calls from different people asking for payment and getting them to get their systems to match is feeling impossible. You get them to tell you who to contact then you do that and you log everything and you are told to wait a week for feedback then you phone after a week and then the story changes and they have to re try something and now you have to wait two weeks and this and that and you are incapable of taking out a student loan because they have made your credit score so bad that you can not even do anything. But yet no one can assist in getting the problem resolved? How long do I need to struggle with this before it ruins my credit even more?