Mastercard? What mastercard?

I was recently under debt review, and managed to pay off all my debt. All accounts was closed by the company who handled my debt review. I requested a credit report just to see a Standard bank mastercard with an outstanding balance on my profile. I had a Bluebean card with standard bank but that was paid up and supposed to be closed. I spoke to the debt review company and they say that the account was not on their list. I need this account removed and taken off my credit report!