Where did you get it?

Steam says that i've got this one....
But i can't see it in store.
Can you please reroll the winner?

This key is "LET IT DIE -Alienware DLC- for Beta Testing" and I already had this DLC from Alienware
Not "LET IT DIE -(Special)10 Death Metals- 002"

I must mark this gift as "Not Received"

And RTFM!

Beta keys, guest passes, and coupons should not be given away.
...
Giveaways should accurately reflect the game being given away. If the game is not available in the giveaway list, please contact support to have the game added, instead of posting the giveaway under an incorrect name.

View attached image.