List on ITC for something I was never told about

on the 25th June ,I received an email saying I owe Mtn R1568,03.i tried calling the call centre n with their recent strike never got an real answers!On Tuesday I received an email from FNB stating they are taking my home loan that I was recently approved in July because A company has listed me as a slow payer!When I called Experion I was advised that Mtn has listed me as a slow payer n I am 2months behind with payments.When I went back to Mtn ,I'm still being sent from pillar to post n on mission impossible to get through to Mtn legal.ive reported to the call centre agents that when being transferred to legal the line cuts!Could someone from Mtn tell me what is going on because they are ruining people's lives.As far as I'm aware ,my contract with them ended in February and paid all outstanding fees!and according to their letter,they have been sending me sms's which I've never received!