Unable to close account at Telkom

Our Company has been trying now since May 2019 to close an account at Telkom. This office has been closed and we have done everything Telkom requests and every time you assisted by someone else and the "story" has changed. A layer has send two letters to their legal department. I have received the current invoice for +R13000 last week. I really do not know what to do anymore. Office assistant.