Set up for classes on own time

When I was hired as the knit and crochet instructor for Michael's last year, I was told by the store manager that I would get 1/2 hour of paid time to set up for the classes. Since then there has been a change in store management and I am now told that I have to set up for classes on my own time. In addition to setting up my lesson plans, handouts, samples of projects, knitting needles,etc., it is usually necessary for me to straighten up and clean the table in the classroom. Frequently, students come in early to ask questions or get help with purchasing the items they need for the class. I am now expected to do these pre-class activities without compensation. Is anyone else experiencing this situation? Are you gettting paid for set-up time or are you doing it on your own time?