Blank cheque as security cheque bounced and case filed

I need a help regarding my cheque bounce issue..i had given blank cheque for the security of a 1 lakh chit of twenty months which was organised by a local person who was residing in my hometown.i had paying monthly chit amount to the organising person up to date.but suddenly he had a loss by some other persons who participated in the chit which i am.the chit organizer left the city with all money who all r in the chits.so after a few days i got a notice from the court from and he filed a case from another person whom i dont knew.i need a help to get out frm the issue