Yes I pmed him twice maybe three times and no response he said he would process my withdraw. Never signed anything ever I don't know how. Well doesn't my pm say that he would process my withdraw ? Now its day 5 still no response.
You may try with Coinbase (clean URL, no personal referral, nor nothing), creating a new account takes minutes (seconds, I would say) and signing a message is pretty straightforward (to be honest, this was the first message I have signed since I use Bitcoin -roughly one year-).
To sign a message there, you click your name in the top-right corner, then "advanced" and finally select any of the addresses there and click "details". There, in the lower part, you have the option to sign a message. A more detailed tutorial is available here, on Coinbase's site.
It takes a few hours to process as pointed out in the PM above.
I would do this favor to you, but you would probably not want one of my addresses associated with your account (also, this would be a longer process, probably you won't trust me, etc.).
Good luck!
As far as the scam is concerned don't worry ,the owner seems to be a nice guy he will pay you out. 
