Help I won a Giveaway

did they activate the game? as it may have been that they got the game key after that

First activate it and mark received if the key works. Then check if they regifted it (did not activate it themself)
Then report them.

You can do whatever you want because you won't be in trouble. The maker will be, if he is actually regifting.
So the nicest thing to do, especially if the creator is new to this website (nevermind that creator joined SG about 3 years ago), is telling him to activate the game with that key you received. If they don't do this, tell them they risk being temporarily banned for regifting.

Regifting is not allowed here and the game is not in his libary.

The first thing you should do unmark it as received since you have not activated the game yet.

use the code, if it works, mark as received, and move on.

So, you don't know if the key works but already confirmed?
Activate it, you won it fair and square.

You're not the one breaking a rule if you activate it, they are so... Take the game and let them deal with the consequences of their actions.

you can warn that person it's against the rules to regift (just be sure he didn't activate it and it's giving away another copy).
or you can ignore it and activate it yourself, it's not against the rules to win regifted games.

btw, don't mark as received unless you activate the game in your account, or you will get a suspension.

Okay thank you very much everyone I unmarked it, and will wait and see how this plays out since i haven't received a key but i will try activating it first and if it doesn't work then i'll let him deal with the consequences.

Thank you all very much, you're all a very helpful community :)