Airtel — regarding airtel hotspot

This is to inform that i purchased a airtel hotspot in april trusting airtel hotspot company as a good service provider.But i founded it With the worst service provider.The hotspot we provided to us dint worked with network even a single day. The biggest mistake i did was the money paid by me.I complained a lot many times but i dint got any response. Hotspot provider dont even receive any call.He dint even returned the hotspot . They are not even refunding my money back.