Please enrich my idea to get justice?

I have been living in USA permanently having dv visa. This year I visited my parents in Bangladesh, my birth place. My parents are living in Dhaka. On my parents request & demand I have built house in our native village. My father inherited the land from my grand mother. After my return to USA I come to know that my 2 uncles usurps this house banishing my parents. They also filed a case to police station against my parents that my parents are living their land illegally. Now I am very pensive to hear this news. Please guide me how to get proper justice for my parents & restore our house. I have invested about US$50000. Please advise me.