First time it's taken someone what seems like forever to mark received.

Try to contact that guy, and if he does not respond, just ask for reroll :)

You can do it by sending them an email.

Or reply to one of his comments here on SG (if there is any :)

If his/her comment field is public just leave a comment on their profile saying he won your giveaway.

comment on one of their old GAs, they'll get a notification.

^

but your impatiance isnt fault of the winner ;)
remind him to activate his game and give him the seven days, he has^^

We will ask you for screenshots of your attempts to contact him. If you don't already have some, now is a good time to get them.