Evanston Technology — fraud calling for money

I m from indore i registered my self with this company with data entry work but i m enable to complete it so according to agreement i have to pay 6500 to them i paid the amount on 16/4/2018 bt suddenly now after tow years they called me and asked me for 15000 rupees and i paid that amount too. Bt now they are saying they haven't received the amt and now they are going to legal action. Plzz help me to solve this i m just a student.