I completed my b.tech in civil and i recently attended a interview for site engineer role,site owner asked me for a two years agreement bond,promissory note,empty cheque and certificates.So i agreed and signed in promissory note & in empty cheque gave it to the company but i didn't write a two years agreement bond in stamp paper.unfortunately due to some reasons i'm not interested in going to the job, now the owner threatening me to pay an amount of 4lakhs to return my certificates.Is it possible to file a case against me?? what are the steps should i follow now. please kindly help sir.