My MTN nightmare

I got a contract with MTN everything was fine until I requested that they change the bank I debt. Fast forward to my nightmare, the account was handed over. I made payment arrangements but I managed to settle the full R18k in three months. August I received my zero balance statement from the debt collector and a paid up letter to take to MTN.. I went to the store and the store said they I had to email legal. I emailed the legal department and they responded after a few days and said they had not received payment, I was told to contact the debt collector.. it’s been 3 months that I have been trying to get this resolved and no one can assist.. the call centre can’t put me through to the legal department, the store also can’t, they are not responding to my emails. The debt collector even tried to contact them on my behalf but they not even respond to them… if you thinking of taking a contract with MTN don’t.. I can’t even use the phone because it was locked yet I paid in full.. MTN is a ****. The difficulty getting through to the call centre is living proof