Worst service from Telkom accounts

After admitting that you had a problem on your billing system where hardware was not billed on the last month of my contract, but instead was billed the following month. to which a payment was made on the 15/07 you still handed me over to NuDebt. I have never missed a single payment in my life and have never had an issue like this on any account you handed me over. The service at NuDebt is shocking and this is who you handed me over to. My Telkom account shows paid up to date but NuDebt keep threatening further action and mails from them continue to come through with threats. This is absolutely shocking and in what world does a company handover clients after a mistake on your billing system???