How long for credit file to update

Rocket1971

Firstly thank you for the advice so far
The default has now dropped off my file after several phone calls but I have now spotted another error as my credit score is 304 and showing a status of poor.
Having checked my file I can see a card I had with the RBS that was on AP but then moved back to normal payment terms and paid off in full but there is a note saying you currently have 3 months arrears or more with a lender. I called equifax who initially advised me I would have to £6.95 to update my score as the 3 months arrears is because the account went on a AP for a while after 15 minutes of me trying to get them to advise me how can you "currently" be in arrears when the account was settled in Nov 2011 and that I am not paying for the error of a cc company or equally equifax , I asked to speak with a manager or the complaints department, I was placed on hold and when the operator came back on the phone she said will will contact the lender and ask for this to be removed from your file the updated record will take 21-28 days, just checking if anyone has experienced this or is it correct that if a account has gone into temporary AP status and then back to normal terms and finally settled in full should your records be marked with currently 3 months arrears thanks in advance