Telkom continue to bill for cancelled service

I have cancelled my residential line on 26/10/2015 and followed up with emails on 03/12/2015 and 11/12/2015. I also phoned on numerous occasions and have paid my account in full until end of November 2015, after speaking to a Telkom accounts consultant who confirmed the correct amount to be paid. Despite these numerous requests by email and telephone, I'm still being billed for a service at premises where I don't stay anymore and a service that hasn't been used since 24/10/2015.