Same here. I still see my received link at https://cubicbundle.com/Gal-X-E-giveaway but no game in my collection and the link doesn't work anynore.
http://steamcommunity.com/app/473510/discussions/0/357286532030964463/ -- found this explanation.That means you should NEVER buy anything on itch.io, since the devs can simply remove the game from your collection any time.