Won a game but received wrong key

Do not mark it as received if you didn't actually receive the game. I'm afraid you will have to mark it as "not received" and move on.

not recived, u still havent recived the right game

Mark as not received if you don't get the game in the GA. Otherwise, you yourself could be banned for not activating keys. He can create a support ticket to change the GA to one of the keys you received however.

Marking as Received could get you into trouble.

Its because of these stupid GMG giveaways for 10 games for 50 cents, where people just sell it all, the keys are randomly in order so they give u the wrong one.

Tell them to give you the correct key or say that you cannot mark it as correct.

Ouch... Well, happened to me with Force Unleashed GA I won. Got a key to different game, that I thankfully owned already. Contacted the GA creator right away and got it sorted out. To make it even funnier - the key I got was for another giveaway by that person, and if I didn't own it, other winner would end up having nothing :(

You could mark it as not-received (in which case he looses a gibs slot and has a permanent mark on his record),
or continue testing the keys he sends until you find the right one and only then mark the game as received (you get the game and he gets the CV),
or you could allow the creator of the gibs to ask that the giveaway be deleted by support (you don't get the right game and he doesn't get the CV but he doesn't have a "stain" on his profile).
Choose from one of these 3 options, depending on what you want and what you can agree on with the creator.

Already asked him to open a support ticket asking steamgifts to change the giveaway to one of the games he gave me, let's wait

Keep ordering keys from him, till you get the right one. :3
And I think that it's your right to do so, because you entered the GA to get that specific game.
It's not your fault that he has so many keys, and doesn't know which is which. :v

I can tell you what I do if there's a problem with the key to one of my giveaways.

1. Check to see if I actually do have the key.
2. Try to obtain another copy of the game to give to the winner.
3. Buy a copy for the winner if I can't get my hands on one any other way.

I prefer to follow through on my promises.

If you don't get the correct key/game, just mark "not received" This is the "good guy" thing to do. Also, return the mistaken keys to the giveaway creator, if you can. (If you end up redeeming them by accident, no worries.) Remember: it is the giveaway creator's responsibility to deliver what he promised, not yours. There should be no penalty for entering a giveaway.

don't be an "a**hole". I mean you have two games ,instead of one

Nah keep it up. Maybe he will give you more free keys then to a point he give you the correct game. I bet he will give you 20 games until he give you the correct one. (Joke)
But if not marked it as not received.