Purchased agricultural land from a farmer pls help

I had purchased a agricultural land from a farmer, obtaining all the noc from his family members sisters,father and mother,etc. Since 7 years their minor sons who turned to be major now,have raised a case on us stating that they have not been given a share and their family members have sold the land when they were minor, we attended the court, everytime the court dismisses the case on us, it's been 3 times that their case is being removed, but still they admit in different court