What do I do when I've won two of the same game?

You should check out this thread where someone had the same problem https://www.steamgifts.com/discussion/BXsjl/won-2-copies-of-the-same-game

Now, this one is actually trickier than the other topic's...
Are you talking about those multi-copies "Wrath of Anna" giveaways?

For the invalid one you can agree to cancel it with the giveaway creator, otherwise a re-roll would mean someone else has to decide whether to cancel or have the giv creator either leave it as not received or have to locate a new copy of the game.

in this instance you wanna just want to comment inside the invalid key's comment section that it is invalid and additionally you have won it already both.. explain to them that if they have the valid key to replace it with then they are welcome to a reroll. otherwise i'd probably just give them permission to delete as well, but that's just me. -assuming they look clean otherwise as far as activations & dual wins. if they look dirty in those ways, then mark it not received after the weeks up.

What would you have done before asking?

Thanks for the help guys! i posted this comment : https://www.steamgifts.com/go/comment/j2Ag0t9