Cheque bounce case against father in law.

I issued cheques to father in law for a sum of 3,00,000 rupees as a gurante for the chit 2 years ago with out mentioning any date after that i paid back the whole amount as monthly installments for the chit during this period because of some family issues we were not talking to each other and now they are thretaing me to file a case against me by producing the cheques to the bank.

Please help me in this regard how can i get rid of this problem will requesting the bank for stop cheque payment will help or if they produce the same on bank and if they got bounced what will be the consequenses and what should i do i am already in a lot of financial trouble and this problem is causing me a life and death situation.Please suggest me what should i do?