Imcompetence at its best!!!!!!!

My Woolworths account was handed over to DMC and I have since settled the account in December 2021. On numerous occasions I have contacted DMC since they still appear on my credit report and the account shows as active. Each time I speak to their staff I am being told that a query has been logged and it takes 7-21 working days to be resolved. Its been 3 months and I'm tired of bring sent from pillar to post. This is frustrating dealing with *********** people. This is affecting my home loan application!