It has probably happened to all of us at one time or another, so, what did you do? I always try to tell one of the employees, but they almost always give me the feeling that they think I did it! Today I just found 6864 at my local Fred Meyers, and it was hidden behind other sets, opened. I told the employee and we found a bag with a few parts and one of the henchmens head, but no body or other figs. There was also one of those tape pieces down the aisle from a different set, since 6864 had all of its. I ALSO saw the bag that Iron Man's helmet comes in next to the Quinjet's. I hate it when this happens!
So what do you do?