I won A Game But

Not a bug, has very easy solution. Wait 7 days, mark as not received.

Try to add the giveaway creator on Steam.
If you can not establish contact, mark the giveaway as "not received" after 7 days.

Sorry if I don't understand it correctly but if the giveaway creator provides a key that is invalid or for another game, mark the game as "not received" and try to contact him. If he blacklisted you and you cannot contact him anymore there is really not a lot you can do as far as I know.
If you tried to activate it and the creator doesn't provide you with a working key it's not your fault, you just won't be getting your game.

it's not a bug, it's an asshole.

It was not hard to find the GA, I left a message for you there.

Did you make sure to copy just the key part if it's a steam key? AAAAA-BBBBB-CCCCC
I once had an extra character at the end of a key and the winner couldn't tell and thought the key was bad.
If it's a humble bundle link or something else you don't just put it into the steam redemption interface.

i rewrite key, it was my fault.

Honestly - look at that game. I'd rather have the SG points back than play that asset flipped POS.

Sorry for the missunderstand, I am going to close the post (if there is a button for that). And thank you all!