as an employee who has worked on the floor and register I can't understand why do managers and supervisors have to display such an authoritarian attitude that put employees down, working on the floor they throw things at you and tell you to pick them up because you’re not doing a good enough job in a very mean and degrading voice, and on the registers they tell you to either do what they tell you or you can go home/ or quit. What kind of company treats their employees like that? And that's why people don't last long working in this type of ambience...
Whoever works there should carry a hidden camera now and then, maybe they can get one of these events on video so they get what they deserve.