What can do to get the cops to follow court order?

My father was married to a women and been separated since 2000. He has a son and a daughter with that women and they were with my father till they were separated due to their problems. Now the women under the guidance of her son filed a petition against my father that my father's assets were earned by their collaborative efforts and broke into my father's office illegally. Even with all the evidence the court ordered the women to stay . Eventhough the court ordered that only the woman can stay. Her son and her sister deliberately stayed with her. Her son damaged the office door inside and refused to accept it. Even the police know that he broke it bu refused to take action against him. Recently we tried to build a barrier to separate the office and working area to do our work without any troubles. But they called the police on us and the inspector ordered us to remove the barrier. Even the court order did not say anything about it. But all the things seems seems to be one sided. What can we do to work without any trouble?