Miss guided for employment what to do.

Hi,  These days hiring a IT prof. on contractual basis is common. I was interviewed though one of the contractual employer to one of its client company, Interview was fine and client was happy to hired me but the client manager then insisted me to get come in to work at his office not though the company i was being interviewed but though his favorite contractual company or may be he will get a commission from his favorite contractual company. He gave me a condition that he will hire me for at least 1-2 year and will give a negative feedback about me to the contractual company though which i interviewed and will approach me though his favorite contractual company to get me hired, in return he asked me to keep my mouth shut on this on which i did so. As he told i was approached though that diff contractual company and was got hired for the same client. but now after 9 months he cancelled my contract for no reason. Any legal advice on this ?????