What happens if I get a gift from someone of a game that I already own on GOG.com? Is there any way to transfer the purchase price toward a different game as long as the gift code has not been redeemed? Or is it just a wasted gift?

My family is giving gifts this year secret-santa style and I put some GOG games on my wishlist. But now with the sale, I'm thinking maybe I should grab some games in case my secret santa gets something else non-GOG from my wishlist. But if they get me something from GOG that I've already purchased.... then what?

Thanks!

An alternative is to trade the code with me for a game you want and I'll use that code for my giveaway or something :)