Against a builder who charges high than agreed amount

The house construction started on 20th august 2014.The building constructor is our relation, he said no need of agreement. He first spoke to us that 1400RS per sq.ft for 1100sq.ft. And he promised for good quality products. He said extra work like bore,septic tank and even grill gate for main entrance, electrical work, doors and painting is ours. His work is just to build a house without all these. we have settled the amount & stopped him doing the compound work and now after an year we arranged outside contractors to do compound work. The builder came and gives him life threaten to labour that whoever comes and touches the compound they will face the consequences showing his power, and telling us(owner) if u start compound work i will make an issue. Give me 2lakhs and then u start doing the work. As per date we have written the accounts in a notebook and ours is full and full bank transaction. He has written a account where he has left out 3lakhs and is now giving life threat when my dad is not there. He comes and warns the ladies in house to pay him 2Lakh than the given amount. 1)He is not a licensed builder. 2)hidden charges 3)Incompletion of work 4)poor quality construction. 5)Gives life threaten misusing his position to the owner and the other workers who now build compound.