Harassment and a *******

I have been communicating with mtn and they asked me to make a payment directly to them. and i have also authorized mtn to debit the outstanding balance from my account but they have not done this. SSDA employees keep harassing me and ignoring the fact that I have made arrangements with MTN and they threaten to add call charges on my account and they have been adding charges daily and MTN is also not assisting me and the debt controller from MTN that I am communicating with takes longer to respond to my emails and these people keep calling and charging me for missed and taken calls and promise to call and harass and charge me for every call. Innitially the balance was R2700 now it's 42100 because these people are calling me daily and MTN Is not helping me.