I settled my account and Finance 27 doesn't want to give me settlement letter 5 months later

I settled my account with Finance 27 on 25 May 2022 and till to date my credit report shows that I owe them and I am behind with payments. I've called them numerous times and emailed several people, to give me settlement letters and they had taken me from pillar to post. This affect my credit score and I had done everything to get settlement letter with no luck.