Appalling Service and treatment to customers

I have been an MTN contract subscriber since 2011. In 2017 I had requested a second subscription account for data which was granted. Earlier this year I was advised that my data account was handed over to a collections company (VVM). I requested the collections agency to advise me the amount that was outstanding so that I could bring it up to date and close the account as I no longer needed. They obliged, I paid the full amount, sent them proof of payment and subsequently received a paid up letter. I called MTN to update them that VVM had provided me with. I was advised that the account still had a legal status with the MTN Legal department. I called in several times with various MTN Service Champions providing references for this request to be actioned. Eventually after two and a half months of battling to remove the this status I was advised on the 11th of May that the account is now with the MTN Credit department. I called the call centre again and a request was sent to MTN Credit to clear the account as it was fully paid. I was advised that someone would call me to provide feedback from the credit department. Today 17th May, I called in again provided the reference that I was given on the 11th of May and I was informed that the credit department advised that I have a R188 that was outstanding, when I enquire what the amount is for I get no answers, I asked the Service Champion why I did not receive a call as I had provided the MTN number to be contacted at once there is feedback. I could not receive feedback still. She further advised that she had to log a call, I asked why I am not able to speak to someone from Credit so that I can receive questions to my answers. I was told that I need to wait for feedback. I am extremely exhausted and would like for MTN to just clear my name from the Bureau as I have paid what was outstanding. This is appalling service and I do not think a Service Provider is big as this deserves the loyalty of customers if they cannot resolve issues in appropriate turn around times.