I Worked In State Bank of India as contract Employee for 2 years 6 months,Due to uncertainty as contract Employee i resigned my job on 25.06.2010 and jointed in PSU Bank as Probationary officer where i have to spend another Two years to get Permanent role,

I resigned on 25.06.2010 SBI Management Observed all such contract employees become permanent as JMG 1 with out any probationary period on 14.07.2010. My question is can i sue against Management for this unannounced decision ?

if they informed earlier i would not have resigned, They given Experience certificate on 13.7.2010 stating that He is very good Employee.

What should i do to get in to SBI again ?