Planet42

I had a rental contract with Planet42 then I cancelled after 6months which my contract allows me, paid up letter was forwarded to me on 02 April 2024 which confirmed that my account is fully settled and the balance is nil.

When I was checking my credit score it shows that I have arrears with Planet42 and the account was not closed.

This is badly affecting my credit score, iam very devastated, how do I owe a company when I paid fully and received paid up letter?