Cannot close my account for my (old) landline

I can't seem to cancel my Telkom line after numerous phone calls and even taking to Twitter. My service was cancelled on 2 Sept 2018 and actioned on 19 Sept 2018, but I still get an account every month. After posting on Twitter and subsequently sending them my reference number, I received a reply on 21 December 2018 saying the following: "I have logged the following case ******xx, for a protection against the account. Once the account is completed, then we ca proceed with the cancellation of the service." Well, I think that just activated my account again. Yesterday, 15 January 2019, not only did I receive another account for 09 Jan 19 - 08 Feb 19, but I was charged R260.21 on 21 December 2018 for "Reconnection Fees". This is the same day that case no. ******xx for a protection on this account was logged. Why was it necessary to reconnect me? And why is it so difficult to close an account? Total incompetence!