contract terminated after injury

[Marlo]

I was employed in a contract situation by a hospital in South Dakota. I recieved a diagnosis of a fractured patella to my left leg and soft tissue damage to my right arm, which is still very painful to even use to turn a doorknob, the ER Dr. never xrayed my right arm on my visit to ER. Basically several days later the Hospital called my agency and cancelled my contract. They did not use my injury as a reason however made up false reasons stating that I was not performing my job, had left in the middle of my shift and had stated that I had a gun in my car...all which are false. Up to this time I never had a complaint by the employer on anything. I feel they made up these reasons to justify cancelling my contract which guarenteed me 48 hours a week for 13 weeks. Can they get away with doing this or do I have any recourse?