Telkom Incompetence could get me Blacklisted?

I have sent a request to have my Telkom Account closed 07 December 2017. I received communication that my Telkom account has been closed on the 18 December 2017 stating that a 30 days notice period applies (which is all good with me). Today, 19 March 2018 I am still receiving a Telkom Bill and I now supposedly owe Telkom close to R4,000.00. Now I have made phone called, been to Telkom Stores etc and each time with the promise that the account will be closed. Also Telkom 10210/10217, Telkom Fibre, Telkom Stores etc don't communicate with each other (so I am told) and the one has to wait for the other before they can stop billing me. In the meantime my bill escalates and how long will it be before Telkom puts me on a BLACKLIST ??? I want to resolve this because I a taking Telkom to court should my name be placed on a blacklist due to Telkom's incompetence.