How to catch cheaters?

1.Sir, I got a advertisement from The advt. was all about an SBI job. However it made me believe on this job as I talked to the recruiter by phone. The recruiter mentioned that the job is related to sending sms to the borrowers of SBI. And I shall get a kit including 4G sim card, Memory card and a laptop mobile in exchange of Rs.2100 by the registered post. But I didn't get those. Infact I got only a letter where's only stating it is the step of your address verification. Later on they are asking for further Rs.5300 for my kits. And also said if I don't send money my job will be canceled and no amount will be refunded. They are none but the cheaters. They are trying to loot the unemployed youth. So far I have come to know that they belong to different state as I considered their contact nos. I also have the letter sent by them. Now I want to know how can I get the legal helps so that they are punished enough under Indian law. Or else they will be cheating the unemployed youth through out the country.