How to get back my original certificates which I surrendered to my previous employer?

Hi Sir/Madam In last year April (2017) I joined in one accounting based company in Bangalore. I signed the contract period of 2years and I surrendered my original certificates to them. Later in Aug17 , As I want to join in distance MBA course I asked the company to give my originals for 2 days period . As I mentioned in offer letter I also agreed to surrender my other original certificates for 2days till I return the previous original certificates. But the company denied to take my other original certificates and asked me to give money Rs.110000 .I don't have that much money to pay. And last date of application also closed. So I resigned the job for the act done by the company and sent a mail stating the reasons on very next day. 2months later I received a mail from company stating that "Company damaged because of my resignation so you have to pay damages for that . And they want me to reply that mail with in 2days otherwise company will take legal action." As I given enough reasons in my resignation mail, I never responded to that mail. So I want my certificates now. What should I do.?