ILR for further checks by HO please help

Hi

my appointment was 16-07-2015 at sheffield (peo)

i m self employed but my application is hold for further checks i have paid all my tax nothing due.

actually wait 3 hours and the case worker turn up and request me to post last three years tax returns with in 14 days but i said i have with me HMRC DOC( SA 302) that covers last 5 years tax i have paid i explain her and also mention
on to write it but she just listen what i have said also said do you want my last extension accounts as well but she said no they have in there record after that she only took SA 302 with her and after exact 2 min she came back and give me a letter that she want to do some further checks i said if you want any more information i can provide you but she said no they have to do more checks

so my question is that any one know how long it will take and what kind of checks

i have paid all my tax nothing hide exact same as the first and second extension all paid

so any one know what kind of checks and how long it will took

Please don't make multiple posts on the same topic.