Credit Bureau not updated on paidup account since 2018

I Have Paid my account up with RCS Spitz in 2018 all the documents were sent to them but nothings has been done to this day. I contacted one of the agents early 2021 and was told that it would be cleared after 21 to 31 days today 19/08/2021 I contacted them again nothing has been done. This has a very bad reflection on my credit report. Please assist me in getting this done and clearing my credit report.