CD key wth?

Gm's i'm sorry i dont know where to post this so please just move it whereever. Anyways. I bought Counter Strike: Source a week ago. I was happy i got it, my friends played it so im like what the hell.. i bought it. Well i go to open it and theres no CD key inside... I was like what the hell. So i then proceed to email a steam representative who tells me theres nothing i can do about it... so i wonder just wondering if any1 can help me out and find a place where i can either get a cd key for free or if they dont play anymore and would like to let me have theirs? I would REALLY appreciate it... any help would be nice

u gotta buy a new one...lol