Open2cart — Fraud company

I have received a call from open2kart.com. They told me they have launched new e-commerce website with payment tie up with payumoney.com. For your first order you will be eligible for an assured gift. and if you are not satisfied with our services. you can cancel your order any time. They made me purchase one item through his site. I made payment through payumoney.com. later they told me release payment through payumoney.com. I did. After my order I searched on Internet and found this is fraud site.and tried to cancel my order by calling these guys . But these guys are not attending my call. even i called payumeney help centre but these guys are not willing to help me. I just want to refund of money for that i willing to take legal action against them also. Please provide me your help to resolve this issue. site details-http://open2kart.com/ its fraud e-commerce site please help me to take action against it my order no.is 10000312 and payment Id is 82714712 through pay u money