J.B.
I was in a similar situation about four years ago at a retail store--not "technically" a manager, but doing all of the work of a manager without any of the benefits (insurance, vacation, etc.). A lot of businesses will do this in order to save money. I don't believe it is illegal (although I'm certainly not an expert), but it is certainly unethical. It is probably illegal, however, to threaten an employee with termination if they do not work a shift that they already told you they couldn't work. If at all possible I would suggest getting out of that situation as soon as you can! It's obvious that they don't care about/respect you and they will not stop bullying you. Also, if you have gone "above and beyond the call of duty" before they will expect it from you all of the time. I would suggest that if you do confront your employers to try to do it when their are witnesses around, so it won't come down to your word versus theirs.
I am going to do some research today and see what I can find out for you. In the mean time here is the contact information for Maine labor issues:
For more information about Maine Employment Laws, please contact:
Maine Dept. of Labor
Wage & Hour Division
45 State House Station
Augusta, Maine 04333-0045
Phone: ###-###-####
Fax: ###-###-####
TTY: (207) 1-800-794-1110
Email: ____@____.com
Anne Harriman, Director
You can get free legal assistance from Pine Tree Legal Assistance (www.ptla.org/) or the Maine Volunteer Lawyers Project (www.vlp.org/) if you meet their income requirements. It wouldn't hurt to email/call them just to ask a question or two even if you aren't planning any legal action.