MTN failing to provide me with the amount due

I was contacted by Saya Recoveries since June/July, made the payment then called Saya Recoveries only to be told that I didn't made the payment. So I went to FNB to verify their banking details and I was told that that bank account has since been closed. Now, Saya Recoveries is calling me again and telling me to make a payment on the overdue account, told them I won't since I was previously de*****ed. I'm trying to make contact with MTN legal in this regard and I'm not getting any joy, I went to the Nedbank Sandton MTN branch and they also tried contacting the legal department, still no success.

This account has been making my identity adverse on ITC, now what does on do in such a situation since my ATM deposit receipt is also worn out?

Is this how MTN treats its customers and no communication is sent out to its customers???