How long can an employer put an employee on suspension without pay?

Question Details:

An employee was harassing me so I playfully tipped his hat (he does it to me all of the time.) He then commenced to attack me. I didn't fight back and was off the clock at the time. He and I were both put on suspension until further notice pending investigation (which is bogus all they had to do was ask the witnesses and watch the camera). It has almost been 3 weeks and no one will call or talk to me; the union has no clue whats going on. In my opinion I should have been written up for horseplay and not suspended. I have missed 3 weeks of work/ pay. What can I legally do about it, including back pay and such? Important Notice