Unless you have some kind of work contract, or there is a collective bargaining agreement that protects you, or there are other policies and procedures in place that the employer is not following and there is some kind of grievance process, Illinois is an "at will" employment state and the employer can change the rules any time, just as you would have the right to quit. So without more it's impossible to say, but those are a few of the things you will need to consider.
