Struggle to cancel my account over period of 2 months

I've cancelled my Telkom account in February 2021. I've send all the documentation as required. I've received a email after I've send all documentation through but no confirmation note! When I call the call Centre - I'm on hold... just to be cut off. That's after holding for more than 20min. If I go to other departments for help they just cut me off. If I don't pay my account it's easy to black list me... this department needs to be held accountable for the accounts if they dont do their work !! When I go to the mall to cancel... yet again all the paper work get filed but with no success! So please what do I need to do to get my account cancelled and to whom can I send my accounts to be settled if not cancelled?