MTN Collections nightmare

I am really struggling with MTN Account. First they stopped debiting account becasue Payday was on a weekend and they could find money on friday. Their collection system is the worst. Secondly i was handed over to MBD. I have paid R8000 to their collectors being MBD and to date those funds are not credited to MTN. I sent emails twice to MTN with proof of payments but account is still not updated. If anything i am now being harassed by other collectors - Nu Debt Management. Can you please update my account and revert back to me with real balance owed.