Telkom Frustration

I am extremely upset with Telkom. I had an account with them which was closed almost a year ago now. Problem is the account shows as active and show a currnt balance which is incorect as the account was paid and closed. I hvae made numerous phonecalls to them each time getting a promise that my status will be updated on the credit berau and a paid up letter to be sent to me after 7days. This has not happened on all accounts. I am extremely frustarted and am at my wits end. can somebody anybody help me out there. What do I do?