Wow Gold Forum www.worldswarcraft.net

It sounds like someone already got to that box and used the key from it. The fact that is was a display case box might mean that someone returned it at some point (and they never planned to actually sell it) or some employee at the store figured it was a free key for them. I would take it back to the store, tell them that the key from the game had already been used and get your money back. I'd probably then find another place to buy it from at that point, but I guess it would depend on how they treated me when I went to return it.