Wheel of fortune gave me an already used Steam Key(?)

[duldaad]

I just got a Steam Key for the first time from the wheel of fortune. It popped up in the G.Giveaway tab as a "Your Gameplay Giveaway won". I clicked "Gift Link" which opened a new page that shows a "Secret Game" and a claim code button. When I copied the code and tried to activate it on my Steam account, I got the message:
"Duplicate Product Code
The product code you've entered has already been activated by an existing Steam account, and is therefore invalid. Your activation of Speedball 2 HD has not been completed."
Did I do something wrong or is it just a scam?

 

[BurningPixels]

I think they give you a key from the indiegala challenges games and Speedball 2 HD has been always reported as duplicated key from the duplicated thread here Feudalife challenge BAD/FAULTY/NOT-WORKING/INVALID keys masterpost (error message: this product code was already activated by a different account)
You have been unlucky, many of us has won duplicated keys from challenges but it's not a scam since it's free.