Missing Serial/cd-key

Ok,

 Here is my problem. I have looked on both the jewel case (cd case) and the manual for a serial or cd key to register to play the game online,  Neither can be found.

 I bought the game at a fry's electronics while I was visiting family in San Jose, CA. I come home to the east coast where I live ( PA ) only to open it up and find out there is no cd-key or serial key in the box to install the game. Next problem is, there isn't a fry's electronics anywhere closer than 534.4 miles from my home. (Joy of Mapquest)

 Is there anyway to get a cd key? Mail the game back to the manufacter for a game with a cd key? Or am I for the lack of a better word "Screwed" ?

 Any help you folks can provide would be better than what I am dealing with currently...

 Thanks