Company given silly excuses to terminate what action can I take

I have started my work as contractual employee in the company for 3 months i agree to work...i denied.for 6 months contract they said they will make me.permanent after 3 months.but HR called me and said that they want to.terminate the contract because i am not flexible.working in night shifts..but the truth is they never allow.female's to work after 7.30 pm.other that that i work good.just because of this silly excuse they want to.terminate me..i.was working from 2 years in my previous company.why i left it for 3 months...if they have these issue with female employee they were not appoint me