my father had filed a civil case for cancellation of unregistered land agreement sale deed .he is 79 years old.he had filed it in cuddalore .the lawyer whom he hired paid only 10000 as stamp duty but while filing he had told us that we had to pay 2,45,000 as stamp duty because the worth of land was 78 lakhs .then my father paid the amount blindly this took place in the year 2018 october. in december2019 the judgement was passed i.e the agreement was cancelled. the lawyer was from chennai so he told that for every hearing he attended in cuddalore we had to pay him to and fro charges we paid 3000 for every hearing. Apart he told that his fees was 10% of the value of the property.but he is ready to take 5 lakhs. now he says that i have to pay him his fee amount 5 lakhs. my father came to know about the stamp duty only in the month of october2019. what should he do? he has not confronted the lawyer.he blindly believed the lawyer.he feels that the lawyer would turn against him and join hands with the opposite party and file a case against him because the case can be opened anytime as it is exparte case.
and he won't be able to sell his land which he has sold as housing plots 1/3rd and 2/3 rd balance left.please advice.