Judgement issue

A 3 bigha land we purchased 15 years back. As the plot having 3.5 bigha in total, but owner sold complete plot mentioned only 3 bigha and mentioned other person in his cauhadi. But that person don’t have any paper for that land. And that land comes under same plot. Now some other person got that part of plot in some paper by mistake. He lodged a case against us. But as the owner sold whole plot to us there is no way he can take that part. He contacted sub-division judge and he give the order in favor of him by stating- opponent do not have interest in this case. Then we move to district judge to reconsider the judgement. After one year my lawyer is saying that here other party contacted judge with money so if you give more money then he will consider other wise ready for high court. I got fed up with this system. I have all my paper and without any checking they just giving Judgement against us. I’m not sure is my advocate doing something wrong or really having problems with judge. One thing I know, I have proper documents and the opponent do not have any valid proof. He don’t have any land near by. Suddenly he jump from somewhere. What should I do now.