Harassment to my age old parents and not allowing us to cultivate land

Dear Sir/Madam, My grandfather got 3 sons. My father is the youngest child. During the life time of my grandfather he was orally partitioned few properties and died without any legal document. My father's elder brothers refused to give our 1/3 share of property. Now my father's brothers son's are harassing my age old parents and not allowing us to cultivate land. Twice I called to 100(hoysala police) at the time of violence. Hoysala police took both of them to the police station but they not taking complaint from me, instead they used to file a false complaint on my father only. Since they get an influence from an local politicians. They were harassing my age old parents daily by using a flith language in public and local police were not taking any action. Local police were registering fake complaint to harass my parents. Kindly suggest me how to protect my father(70 years) and mother(65 years) from these peoples. Thanks and Regards, Narasimha murthy