So I decided to take the game back with the "I bought it for my little cousins birthday because he really wanted it, but someone else got it for him can I exchange it for credit" excuse. Since I a,m 4 days past the 7 day limit.
Then, I did some research and found a pending class action case against them.
I am going to go in with the nice guy approach, and my birthday excuse...if they give me the slightest notion of hesitation or attitude I am going to bust out the 22 page class action suit filed against them (not more than 2 weeks ago) and threaten to call corporate if they dont give me my expansion pack or a full refund for misleading me.
http://ps3.ign.com/articles/107/1079852p1.html
I suggest you do the same once you are done with it.
I'll let you know how it goes...