Second, you won't be able to get any refund for Steam gifts that you have already redeemed. You can only get refunded if you bought the game with wallet money and played for less than 2 hours (I think, not sure).
https://support.steampowered.com/kb_article.php?ref=6643-QEUV-0459#redeemed_gift
http://store.steampowered.com/steam_refunds/ (check under Refunds on Gifts)
It's actually possible to request refunds for gifts received from someone. But I doubt it's easy and worth the trouble with the use of dispenser bots. You can also request a refund for gifts bought from funds other than Steam wallet. I've heard that even people using partial payment with wallet and other means got refunded the way they bought the game or just Steam wallet if refunding to the other source isn't possible anymore. I don't have any personal experience with it myself though.
