DMC and TFG not updating my account

i had an account with Identity that i settled on the 1st of July 2019 and now its been 2-3 months since i settled the account all of a sudden DMC reflects on my credit report that i still owe the account, i called them, they told me to call identity when i call identity they say the money was transferred to DMC and they cant send me any Proof of payment. what am i supposed to do as this reflects badly on my credit report. I have never received a call from DMC or a letter of payment 3 months later after the payment they say, they bought my account from Identity.