SSDA are Vultures

I had an account with Markhams that I forgot about, years later I get a call about the account being in arrears and that it has been handed over to SSDA. I called them and settled the amount they said I owed and received the clearance letter, Months later they are still indicated on my credit report.

Why haven't they cleared my name? Is this how they operate. Where can I go to get my name cleared from these vultures.