permenency

i was appointed in kerala psu company in 2013.The job was adv. like contract basis(likely to make permenent on araisal of permenent vaccancy in future).My appointment letter also mentions same condition.There was no period mentioned in appointment letter.5 months before govt had sanctioned post .but now conpany is going for fresh recruitment.i was working with the hope that i will be made perment once the post is sanctioned.but now im very much disappointed by companys move.what can i do ? can i move legally ?