Billing account

I have been trying to cancel my line and paid the bill up since march 2017. Every month I am getting a new bill still. I have visit Telkom stores, being nice, and still the same story, anither bill. The telkom agent zandile, phoned me on the 13th of August, assure me everything is sorted now and acc is zero. I am so angry with this people. They are promising and talking and not doing their jobs. Because of them I must pay another R156, after paid R4600, then R1200. How much more do they want. I want this account balance zero, no more stories and excuses