Paid up Telkom account

I have paid my Telkom account at Telkom i have received a paid up letter from Telkom and these people are still phoning and sending emails regarding an account that is paid up and closed. They refuse to remove my name from all credit bureaus if they don't remove it within the next 48 hours they leave me no choice but to report them to the ombudsman. The account number at Nu Debt ND *** and the account number at Telkom ***.