Confused on the discount.

I have all three of the previous Sins titles. I had been monitoring for Rebellions release through the Gamestop software I use to start the game. Nowhere that I saw did it state a preorder option with a discount was available. I did see preordering as an option but the ad didn't mention its being 10 bucks off. I would have done so. So I bought a copy this morning and a friend mentioned reading about the ten bucks off and I feel a lil snooked. Is there anyway for me and others maybe in my situation to get a 10 dollar credit for the collectors edition upgrade or are we SOL?