Settlement of account

I am having a huge problem with this terrible company. I have been paying my account after I cancelled my contract and after receiving a balance of 0 a month later I receive another amount of R499.49 outstanding. This amount was also paid after considerable problems trying to find out where the amount comes from. Thereafter I tried calling them to provide me with a letter stating that all outstanding balances have now been settled they say that my account has been handed over to their collections department. Can you believe that nobody in their call centre knows what the number for the collections or legal department is. The people I spoke to where Noxolo Potile and her supervisor Zolile Ndunge. When asked what the managers number was I was told that she was not available one(Patricia Jack). These people are so rude and unhelpful when speaking to them on the phone. One thing is for sure...my every experience with this provider has been a disaster. I will never again do business with these people and I do not advise anyone else to do so either.