Exhausting Services from NuDebt Management/Telkom

For months i have been receiving emails and calls from Nu Debt Management about me owing Telkom money (which i do not) and for months i have to explain myself as to why i owe Telkom no money. It was explained to me that i would have to email NuDebtManagement all the information i received from Telkom to sort out the mess (which i have done) and still nothing has been sorted. When i received another call asking that i should pay the money, NuDebt says that i should call Telkom myself to sort out the mess, which i did months ago and it was sorted then. So exactly what more am i suppose to do as they so quick to add BAD DEBT to your credit.