How to sue packers and movers for theft of personal belongings

I have recently shifted from Bikaner to Haldia through Superfast Packers &Movers. When I first discussed with them they assured me that goods will be packed and handled properly and same will be transport through closed container. In reality they mishandled the goods and send through open truck with others material. As a result major items like sofaset, divan, wooden mandir, steel kitchen rack, d2h, trolly bag damaged and out of 56 cartoons, 12 are missing. I have to paid full in advance. Also paid for insurance but they are not providing me the copy of insurance. Now they are not taking any interest to resolve my problem. Some valuable items like computer, dinner set, nonstick cook were, mixture grinder, clothing, cricket bat, and crockery are missing. Kindly advice what to do. I have written to them several e-mails but not get any reply.