lol wtf

wait. try contacting them. if nothing works, ask for re-roll and wait.

Well, since you alr4eady waited a week on one you can contact support for a reroll ticket.

what if s/he has a s/martphone and waifu wi-fi to enter giveaways but doesn't log in to Steam? =d
or s/he uses a robot to enter giveaways! =P

This happened to me. All I did was take a screenshot of me trying to add them on Steam and trying to contact them on SG. Asked for a reroll, and put those pictures as evidence

Try commenting in one of their giveaways or if not available search for a thank you comment to something they won. At least your winner will get a notification and maybe will reply.

Have you tried to comment in an old giveaway of the winner (in case they have created any) or write them an email?