What happens if someone doesn't trade the reward?

Mark 'Not Received' and continue with life.

Make sure you've check your email,it might have been sent there. Maybe the guy is simply offline,didn't see your request or thought you were a bot. Try leaving a comment if his privacy settings allow. If nothing works,mark as not received. Nothing really comes out of it except the guy doesn't get anything for that giveaway and if it happens too many times he'll get banned.

Kill his family ..We dont want to see a baby scammer..

You have to buy the game that you won and make a GA.

On the 7th day he rested and marked the game as "not received".

Seriously though, I recently had the same issue. Less than a day after I marked the game as not received I got an email from the guy apologizing for the lateness and he came through with the code. Hopefully you'll have the same luck.