What should I do in this situation with my employer?

Welcome to the world of retail sales. You have two options. One take all the crap that they give you and thank them for it until you have put in enough years(decades) to be in a more than min wage position. Or go to school get an education and get a real job where you will still have to put up with years and years of management abuse but you at least will be making slightly more than min wage (you will also have huge amounts of student loan debts though) Sorry life sucks, there are no easy answers, nice guys finish last, etc.