Absolutely useless admin department

I had an account with them that ended up In arrears. I paid the account in full and closed it. I recieved my account closure letter however according to Trans union, compuscan and experien. My account is 5 months in arrears. I've been requesting for this to be updated for 3 months now to no prevail. Useless company. My credit score has gone to **** because of them.