Blacklisted for nothing by these ********

I'm sick and tired of mtn I've been dealing with this for 3 years and until now I can't find solutions. Imagine being blacklisted for something you didn't do and cannot rectify no matter how much you try. I paid them in full and I kept telling them and they keep acknowledging that I did and yet they sent me to their lawyers, i finally gave in and decided to pay ,guess what ..the bank said they couldn't because the reference numbers is wrong, I called their lawyers CSS to get clarity they said I must use my mtn number or ID no as a reference but I still couldn't pay , they advised me to go to their stores. MTN springs mall consultants were rude and told me to buy an mtn sim card to call them again ,MTN carnival mall checked and confirmed that I dont owe them a cent it's been paid in full. I then called the lawyers to inform them Beauty Baloyi was so so rude and told me she can't help me , what must be done really to help me. My whole life could be ruined by something beyond my control. I've been stressed and depressed by this.i don't know what to do now . Please be aware that this is the trauma you'll get when you get a contract with these ********