Billing not corrected yet after 3 months

Good day. I stopped my services with Telkom effective end of September 2015. I still had an amount outstanding to be paid. I then received another statement which has charged me for the month of October, a month which I had no active services for. So I refused to pay the final outstanding amount until the billing was corrected, just in case I was told to pay that amount for services I never had. I have decided to pay the outstanding amount, but the billing was not corrected, I am still receiving statements with the amount as outstanding and payable