Albertsons review: unethical behaviour

I work at Albertsons. I just recently started as my first job. since I have been working for starters no one follows the policies that I read in the handbook I was given to read. at the Albertsons I work at they have a chart of who is supposed to be returning carts at what time, I have carts till 10-2 (according to the chart) I did carts till 2:30 though. as I was about to clock out I get yelled at by a checker who decided she was gonna do carts, she came to the break room where I was and yelled at me for not helping her with carts, and accused me of hiding in the break room. not to mention she did this in front of about 7 other employees in the break room. and when I called a manager after going home crying, she said she was one of those in the break room and I was not being talked to rude.