Telkom ********* listing

We recently overpaid our telkom account, which is now in credit and a refund is due. Even with all of this, telkom proceeded to list our details. How is this allowed? How is this legal? Telkom does not respond to queries, I have spent a good 3-4 hours a week trying to have this resolved and the listing removed, the listing now has been updated to written off but yet has affected my profile record! This is truly unacceptable and so *********. The account number ref we received is :account no:***. Hoping someone will eventually assist in resolving this.