Sued for Legal breach of contract?

I was in talks with a small indian pvt ltd company for a job over phone. they sent me an email with designation and annual salary (no conditions of employment were mentioned). they asked me to reply to the mail with initial acceptance & joining date and in return they promised me to send official offer letter. i replied with initial acceptance & joining date. then next day they sent an official job offer letter over email with tons of terms and conditions, they asked me to sign and return official acceptance letter over mail. i didnt like the terms so i didnt reply to them and i didnt join the company. now they threaten to sue me for damages, defamation, loss of reputation, etc. tell me what i can do ?