Close my Mtn account!!!!

Mtn is a **** company, very bad service. I called in 4 times wasting my airtime which no one was able to assist me. My contract ended end of August and made an arrangement to pay the outstanding balance and I was told when I pay the outstanding balance my contract will be closed and now they giving me a run around not wanting to cancel my contract. I paid the outstanding amount today and now they are telling me that the account is on month to month which I never agreed on, I want nothing to do with mtn and their bull**** service. I just want them to close this account that's it and they don't want to close it. This is really irritating and very annoying.