What does this actually mean ?

What does this actually mean ? When an employer hands you a Staff Policy Packet , and it states your expectations day by day etc. Well in my Packet it states that I have 4 days to meet a goal of 250 dollars a night. By the way I was handing out information about the company and also asking for a small donation. Anyways on my second day of work I was terminated , without any reason. I did nothing wrong I worked to the best of my abilities and I believe I was wrongfully terminated. I know its something I can do in order to get to the bottom of this and to make sure this doesn't happen to any other employee of theirs. I was supposed to be given a warning and I was not given one ! What can I do ?