dowry, pre marriage harrasment.

Hi experts. Plz I need ur advise urgently. My sister's marriage was arranged with a guy in Dehradun. We belong to Panipat. First before engagement when they came to meet us they, guy's family said they font need any dowry. But soon after engagement they started showing their true colors... They asked a lot of dowry after engagement was done. Somehow my father succumb tobthem and we agreed to their demands of dowry. But looks lyk they never had enough. Now the wedding is due on Saturday, 18th jan,2014. And just today they are still asking a lot. When refused they said they don't want this relationship and said to come and collect whatever we have given. My father has spent his entire savings in the arrangements and he is under credit till neck. He was literally crying today.. sir plz help me wat legal action can be taken. I mean can we file a complaint againt them. Say for dowry demand or molesting my sister as , if the marriage broke just before three days it will be really difficult for us to find a new match for my sis.. plesse reply. Ivreally need some guidance. My brother is planning to take some drastic steps. I dont want to see him turning into a crimal. Neither do I know any political or social person.. Plz also reply at. "mr.rohitkatariya@gmail.com"