Unfair treatment and harrasment

They are ****ming for a paid up account thag I settled with Blue Label Connect in May 2025 already they are claiming that they bought the account from Blue Label Connect in January 2025 before I settled it and I provided them several times with the paid up letter and proof of payment but they are not removing me on credit bureau as they reflect in arrears I know nothing about Nimble Group the only creditor I know was Blue Label Connect ofwhich I paid the account in full I was provided with a paid up letter