Paid up letter!!!!

I had an account with HiFi Corporation 3-4 years ago which i paid up years ago.<br> While checking my credit report a few weeks ago, i find that they have a negative listing on my name. <br> I was then advised to get a paid up letter, which i need to forward to the trans-union.<br> <br> After calling 3 times and requesting that this be sent to me, Every consultant informs me that i will recieve it within 48 hours. 2 weeks later i still haven't received anything.<br> <br> You are affecting my credit score. Sort this out immediately, or i will take it to the Ombudsman.