Breach of Contract

[needinghelp]

I was working for a place where I was promised that after 6 months I would recieve full time benefits. I had signed a contract and all. I started there July 10, 2009 and on March 12, 2010 I still have not recieved those benefits. I also found out that I am pregnant and would have liked to have my insurance when I was promised it in January. When I confronted my supervisor he just told me that now it was a pre-exsisting cause and that I would not be able to get my insurance now. I ended up quiting on the spot. I am wondering what I can do to this company to open their eyes to the corruptness they have. Please help me!