Didn't get my code from winning a giveaway, its been 2 weeks +, what do I do?

Looks like it was a humble bundle gift link so it might be sent to you by email. Did you check your email?

Please, check your email, you won a giveway! Gift link sent to you!

¯\_(ツ)_/¯

Quote taken from a comment on the OP's steam profile, for those wondering.

nothing
enter other giveaways
blacklist the ga creator
mark as not received
complain in the forums
threaten him
improve your sg karma by giving something back
send a support ticket

pick the ones you think are correct.

Delete this
Check your email
Mark as received or non received
Move on