Fired because I didn't ask permission to quit!!!!

[auroreg]

I'm from France and I'm doing an Internship in California,a week ago I said at my company that I was leaving earlier because I had another opportunities outside United States. My HR director refused to take an appointment with me, and told me through her assistant that it wasn't a problem. My direct manager told me the same thing. So I confirmed everything!:angel
After 4 days my manager came to see me and told me that actually the date of my departure was a problem because they schedule 3 people in vacation in the same time! And she asked me if I could change my departure date. I told her that I will try but unfortunately because they told me that it was ok for me to leave I confirmed my arrival date with my family (that I didn't saw since 15 month)and the date of the beginning of my new job!
After talk to the agency who sponsor me for my Internship, I did a resignation letter and gave it to them day before yesterday!
And yesterday they fired me, saying that I decide to quit without their permission, and it was unacceptable!!!!! (The HR manager writte that down on an e-mail that she send me!!!!)
So I would like to know what I can do legally against them, because I really don't think that in USA (like in France),I need any permission for quit my work!
What can I do?:no:

 

[cbg]

While you don't need their permission to quit, they do have the right to decide when your last day of work will be. They can let you go earlier than you want to leave. They may not have handled it in the best possible way, but they violated no laws.