Disturbances and vandalism by Land lord of Apartment

I am 27 Male mechanical engineer and a resident of Debangan Apartment, Barasat, Kolkata-700125. My Father Mr.Paritosh Bhowmick after retirement owned a flat on the following adress where our family of 3 are residing. Since day one the land lord of the flat happenes to be the most irritating element in the flat due to her most ferocious and disgusting sense of humor throbbed on all the flat residents. Her sister being the other resident of the same flat has added upon to our grievances. The land lord still wants to force upon us that she happens to be the owner of the land and she can do whatever she wants. Inspite of several meeting's by flat owner's association she refused to cooperation of systematic procedure of following activities of flat maintenance. My father being a senior person voiced of all tge nuisance created by land lord and family in meeting's sore upto the fact that a family member of the land lord has attempted fatal physical abuse. Verbal abuses to such a senior citizen has now become common. Common dustbin in flat premises has been vandalised by the land lord. The stairs has been occupied in such a manner that Senior citizens of the flat find it difficult to communicate. In one such incident the son of the land lord poured water of commode from veranda during morning walk on my elderly Mother. She also happens to vandalis our kitchen garden, shoe racks. While my passage to office the land lord showers upon us filthy word's which are way humiliating in public. Our several requests to her have gone unheard. Now she is demoralizing my parents whenever they happen to pass by branding them as thieves and me as a son of thieves. Its been 7 long years we all flat members association has reported the same to our local counsellor who requested the land lord on several occasions to cease to her irrant behavior. But every request made was in vain.I would like to file a strict case against her and family for committing the most diluting misbehavior to Senior citizens, and causing harm to one's moral by both physical and verbal abuse. The land lord is surviving with his son alone and her elder sister is residing on the ground floor with husband.