Because of MTN I may be Blacklisted...

I'm not even sure if I'm blacklisted already or what. MTN has the worst customer service and never ever prioritises. It's been 4 months and I'm still waiting for them to sort out a payment that I made for Nov. It would now show 5 months that I've not paid my contract. 5 months that I've been running around like a mad man trying to sort this out just so I can give them money. And the store workers are useless. They said that they would assist me and to wait 14 days. After 14 days, I call up customer services and they tell me that my account is gone to the legal department and that they would call... 2 months went by and I haven't received a call.