posting abused comments and article in facebook

Dear Sir, I need a suggestion from you. One girl cased a file against me and my parents and on her husband parents that we both got married.. Me and my parents we took stay for this case. Whether it is true or not court will decide at the final movement. But the lady who cased file against us was creating nonscense thing like the below: 1. Posting comments in facebook by using abused languages and also posting some article in face book by using bad language. 2. her brother has came to my home and creating non scenes when my mother when she is alone in house …immediately she reacted and she called to my brother and both went to police station to file a case but police person has not filed a case and he just register a compliant in his register . 3.they are making fake call to my family members and black mailing us that we are calling from police station we need 5 lakhs if you dnt give we will not leave your daughter. Please help how to take action against them … All these thing very making me tortured and mental stress. As we have very good reputation in society and my parents were feeling bad about it and unable to do anything.. Pls help us what to do ,how we can file a case against them…