Harassment and torture

Hello.... My sister got married to a guy last year. During wedding they tuk 1 lakh money as dowry and they demanded a nice wedding in a costly hall we had minimum 5lakhs expenses during wedding. After a year they sent my sister to delivery she gave birth for a Boy my mom paid 1lakh delivery expenses during the period the baby boy was critical for a day the docs shifted him to another hospital were my sis husband paid 1lakh after that day he and his family misbehaved and totally harassed my family by saying we are poor and tortured my sis not taking wit her, saying bullshit bout my family we asked them sorry also wit out our mistake den too that fellow misbehaved with my uncle and dad.. he is allegations are that my mom is olwaz asking money from him and my sis is not proper 1s he came to receive my sis and he did not come in our home. We went down and called him he gave bad words to my dad, mom, uncle, and sis so our colony people banged him and his uncle.. . The master mind behind ol dis is his uncle know we have filed a dowry case but police is not so quick in the case please help me any 1 wot to do