Non compete agreement clause in appointment letter

Dear Seniors, Kindly help me, I have left the company last year by putting resignation and clearly mentioned that I will be joining same nature of business with other employer, the same is been accepted by employer done F&F by deducting my notice pay days and provided relieving letter, on the very next day i've joined other employer, few days back I have got a letter from previous employer stating that you have joined our competitors thus violating the clause of appointment letter and have asked to provide one year salary as a loss. "As appointment letter mention that I can't join any competition for 1 year "The letter is been replied by me stating that as per section 27 I can do a lawful profession, as non compete clause is void and thus unenforceable, as there is no cooling period nor appointment letter is REASONABLE ,the geography where i can't work, if I'll be unemployed for 1 year how my family and I will survive. also there is no fixed term employment mentioned in appointment. Now they have sent another mediation letter from court. Kindly let me know the further proceeding. Should I go to labour court & put mental harassment case on them.