[Resolved]  Prime Solution — threatening

Address:

Aurangabad, Maharashtra, 711110

A company named prime solution offered me a job of form filling. They gave me an offer letter and an acceptance letter where they put a logo of prome solution. The document doesn't holds my signature or anything where it can be shown that I've accepted the offer. Now when I found that the company is a fraud organization I denied to work for them. Now they are threatening me via email and phone calls to pay them a rumsum amount of money. What should I do?