wrongful termination

Last week I was terminated from my position at a very large corporation. It started about a month ago when I was demoted from a supervisor position to a lead operator without any cause or reason. I in turn informed them that I would stay through September with the company because I had signed an agreement to stay prior to the company moving to another location but that I would probably be leaving at that point. The new supervisor that they had hired after my demotion started her position last week and the 2nd night she was on board terminated me. It all started very innocently on my part when I overheard her telling another supervisor that one person, who was in charge of a particular job, was ill and leaving for the night and she couldn't understand why nobody else was trained to perform that job. So I stopped for a minute and told her that several people knew how to perform the job including me although at the same time told her that I was slow at it because I hadn't done it very often. About another hour went by when she came to the area where I was working and asked me to perform this particular job which belonged to another department and I had been ordered by top management who had demoted me to only work as a lead in the one department where I was working. So I told her it was a good time for her to learn this job and also informed her of another supervisor who would be able to train her. Several hours went by and 3 hours before my shift was to end she ordered me to perform this job which would have taken me a good part of 6 hours to perform. I told her no and she sent me home saying that I had something against her, that she would be contacting human resources the following day and her last words where "that's it". I went home as ordered and wrote an e-mail to human resources explaining my side of the story and received a phone call from human resources stating that they didn't want me to come back.

Normal company procedures before terminating a person was a verbal warning, a written warning and then termination for each offense against company rules. I received neither at any time during my employment. A friend of mine told me that it is a wrongful termination and I wondered if I have a case against the company.

Please let me know.

Thank you,
Karin