Thanks, I had no idea. I just contacted site I got it from, but if agreed to and possible please delete giveaway.
If it helps, I earned credits and purchased from keyjoker, and this is only second key I've got from that site, so I'll be aware of possible issues in the future with any keys from them.
Sorry for issues, I was under the impression any key from them should just work.

Commenting on your own giveaway does nothing. You need to reach out to them with a comment on their own giveaway, with a comment on their Steam profile wall (though be careful about that and mentioning Steamgifts or even a link - their scam check bot doesn't like either) or send them an email - you have the address on the winner's page for exactly that reason (to contact them).