Apalling service by MTN

My contract was wrongfully suspended due to "non-payment". I make diligent payments every month. Proof of payments for more than a year had to be sent to them. Upon follow up, I spoke to 5 different consultants (of which one put the phone down in my ear). I gave them the reference number received from MTN as confirmation of my pop sent... I was told that the reference number does not exist??? I had to travel far to visit 2 MTN Shops, where a consultant was willing to assist me at the second shop. She confirmed that the suspension was wrongful and that there is something wrong on their side. She has escalated the matter. However, I had to phone the Call Centre again and was told that the account is in arrears. I have explained to the consultant who introduced herself as Caroline, that I am aware of this and I am following up on the case...she accused me of shouting and put the phone down in my ear. (Ps My voice was raised, as the consultant could not hear me from the start...I did not shout).