CLEAR MY CREDIT RECORD AND SEND ME PAID UP LETTER

I called mtn regarding my contract that have been flagged to legal department. They advised me to pay up my balance and they will clear my name which i did pay on Absa bank. Since after paying, i have been calling them which i do not for how many times promising me that they will get back to me. But my wait is in vain. I do not where to go. if i go to their branch they tell me they can't resolve it. I even now thinking of calling my legal team to take them to court. What i need is for mtn to clear my name on credit bureau and give me a paid up letter. No mtn consultant called me to try to resolve my problem. this is POOR CUSTOMER SERVICE AND ONE DAY MTN WILL LOSE LOYAL CUSTOMERS.