If I get scammed, can I ever get back the game?

Not much chance. I've got scammed to, I contacted the Support but they don't respond.

Probably not. If a key/money was involved in the trade it is your own fault and if not then how the hell did you get scammed. They clearly say that you should only trade within the trade window. If you have proof of the scam you can contact steamrep,but that won't help you.

But ofc you can still try and see what valve does,but I wouldnt have much hope.

I read somewhere that you may be able to request the retailer (where you got the key from) to ask Steam to revoke the game from that scammer's account. Not sure if that always work.

I think steam will get you your game back if you can provide a proof of purchase. I've heard of some people getting scammed by buying a game like that then having it revoked when the other person claimed ownership of it. Just tell them someone stole it from you somehow. or the key was used when you bought it (if physical media).

I have also been scammed recently, It stings man. It bloody stings. I'm still waiting for steam support to answer me, If they don't then I'll do what iamjellyman suggested and get them to revoke ownership.

Lol no

If you traded a gift, then yes, you can get your game back, even if they gave a key. You just have to be firm and insistent, but polite. They gave me back my copy of Homefront as a gift even though I traded for an FTL key that was chargebacked.

If you used a key though, sorry, but you're out of luck.