What's worse is when you get a downvote by a level 0 user with no giveaways created, no trades done, whose first action corresponds with the day you created the giveaway - and who you see on Steam playing the game they just won, while the time of the giveaway and the time they have on record in that game correspond directly.
1.) Advice from IG is to contact them on Steam - blocked after invite (no other contact)
2.) Contacted IG to report/complain/appeal - told they couldn't do anything unless the other person contacted them.
3.) Asked them to examine his account and try to contact - response after 20 days is, "They never responded, so your feedback stays negative."
I've never created a giveaway or trade with secondhand keys; only my own, because I wanted to be sure... and in two cases now, I've paid for the privilege of giving them away... :|