Can my company cut my pay rate and give lower level job to me on returning from short term disabilty

I have been working for a company for less than a year when I found out I have breast cancer. I tried to work my job and do chemo but my company said that they would put me from salary to hourly so I wont get paid for the time I am off. Then they came back a couple of weeks later to ask me to go on the short term disability they have and I would be covered if approved for partial pay. They were super nice and told me when I come back I would basically be on a different job function but really a lateral job so same pay and authority. No that my cancer treatment is done and I advised of my return date they tell me I can come back to a hourly job making over 2$ less and hour and I would be a regular employee not a supervisor. Can they do that I thought the had to keep me at the same pay rate even if a different job function here in Michigan. I get the feeling that they want me to quit but then I won't get unemployment right.