Isn't it more of a contract between the publisher and the distributor? I mean, we always get nice notes on how we're not supposed to sell it, but rarely do we actually have to sign a contract as store in which we promise not to sell it. [Incase of everything Blizzard and Call of Doody]
Do you work for a small store or a branch of a larger chain?
My guess is the latter, which would explain why your store didn't sign anything. The documents would have been signed much higher up. I worked at Best Buy for a while: individual stores don't have any say over what games they do or don't carry. They can only request supplies, but the decisions for what to carry, etc. are all made at a corporate level.