I apologize that you ran into this issue. It did not inform me that there were any region concerns for this game.

The only options are that you can accept the Steam Key, and turn around and create your own giveaway with it. You may run into the same Region Locking or you can give your permission to delete this giveaway. If you want to have the giveaway deleted, simply reply stating that you give your permission to delete this giveaway.