Enlisted as a bad payer by MTN, knowing fully well i don't owe them

I spoke to Mr Williams Mentjies, Ntsudzu Nutheiwane and Alison Van Der Merwe of MTN to assist and update their records to reflect that I don't owe MTN. Despite Alison Van Der Merwe admitting that their store was negligent by not closing my account and letting it run interest their records still reflect that I owe them and they have even handed me over to attorneys for a lousy R40. 00 that i dont even owe them. I went to the store to pay this money even though i don't owe them, desparate to resolve the situstion but I was told since I have been handed over the legal department has to deal with it. That legal department is so useless! What MTN fails to understand is that one's credit score is an asset that takes time to accumulate and they have messed up mine time and time and again due to their stupid negligence!!!