I won a giveaway but the creator of this giveaway is offline 1 week agoo

You wait, and then mark as unreceived after a week if nothing changes.

I'm going to assume they popped on once, made some giveaways and then never returned, right?

Mark as not received and then move along after a week.

I won a giveaway 1 week ago. The creator took 2-3 days to send me an email with HBundle gift link, which was already used. I replied him, I told him what happened and I sent him a screen capture. I also added him to Steam. A few days after, he still keep my friend request and didn't reply to my email. And yes, he logged into Steam after I sent him the friend request. Today, finally I marked the giveaway as not received.

Wait until the duration of the 7 day waiting period elapses, and mark the giveaway as not received.

You need to wait hr has 2 week to send you te game if he don't make this.Report him and you will become your point back+ the game on steam