Wrongfull account not yet deleted after sharing all documents with them

Good day,

I have had both OnAir account and Hollard which I have provided all prove and required documents but to this four Months later Experian and clearscore has not yet updated my profile accordingly. OnAir wrongfully admitted they made a mistake. I was never there client and I have never owed them which they admitted and even send the cancellation letter which I have forwarded to both clearscore and Experian in so many occasions, four Months later that account still shows as active. This is just unfair and wrong by both Experian and clearscore. What else must I do to get my account updated?