NuDebt threaten with SMS but do not respond to queries and submissions

Telkom Mobile hand over their debt collection to NuDebt who conduct their business irresponsibly, without regard to good business practise. I succumbed to Telkom Mobile marketing in 2015 (then 8ta) and contracted an LTE wifi service from Telkom. It did not meet promises nor expectations. I cancelled the service within a month and then attempted to return the router - Telkom made this impossible to accomplish, refusing to accept delivery nor advising alternatives. Telkom persistantly app**** debit orders for large unexplained amounts. I naturally reacted by instructing my bank to reverse same. The "debt" was handed to NuDebt who simply added SMS threats to the application of debit orders. Eventually sense seemed to arise when Dineo Maleho from NuDebt advised on 8/9/2015 that Telkom had instructed that the file be closed. I have now discovered that NuDebt recorded a debt write off in Aug 17 which *****s my unblemished credit record. NuDebt fail to respond to my written responses and requests for corrective action.