Advice regarding neighbouring plot acquisition

Just beside my home(owned by my mother) there is a fallow rectangular(almost triangular) plot around 2 decimals sharing two sides with us and other two with the street owned by my own uncle who has some personal issues with us. Now, despite of using that plot for any meaningful purpose, he is doing stuffs which are causing harassment to us. Like, planting big trees just beside boundary, damaging our boundary wall, dumping garbages, always giving slangs to my father from there for no reasons and many more. Even approached him for selling it to us at his price but he denied. In a plot of that dimension he can't do anything fruitful except causing nuisance. Now I came to know that he is planning to sell it to someone else at a very cheap price, but will show big amount on papers. So, even if I go to court for claiming, firstly, it will be time consuming and secondly, it will have to bear a huge amount with no certainty of outcome. Please advice me on what should be my course of action in both cases(if sold/not), so that I can get that plot and teach him a lesson.