Go in there and take $500 worth of stuff to the check out then ask them wtf! When they tell you why, tell them to take their stuff and pound it up their asses!
That's what my son did to Walmart several years ago. He took back 800.00 of Christmas stuff for the kids because of a stupid policy. They changed the policy but to the best of my knowledge he's never been back. But the DIL does have her eyes checked there then buys glasses on line.