Section 138 - stop payment of cheque

Sir, I gave an interview in a organization where they asked me to sign 1 year3month of Bond and took Cheque of 30000. I not signed any paper of the company and issued a cheque without date as I was in need of the job. In the offer letter, a line was mentioned, "If you accept the above terms and conditions, we appreciate you could confirm your acceptance by signing the statement below and returning the duplicate copy of your offer letter by mentioning your date of joining. I have negotiated, agreed, read and understood all the terms and conditions of this employment letter as well as Annexure here to and affix my signature in complete acceptance of the terms of the letter." I go to the office on joining date...after three days i said I'm not coming because of family problems. I not signed single paper of the company. They submitted the cheque in bank and i stop the cheque. Now, they said they will file the case against returned cheque under section 138 stop payment of cheque. I said not signed any paper.Then, they said okay,you not signed any paper but you give the cheque so we fill case against you.Please suggest, what to do next. Hoping for early response. Thanks in advance.