advocate charging % of property value as fee component

My advocate is fighting a case for me against a realtor for getting the land registration at our prefered land.

After taking periodical payment for over a year, he charged an exhorbitant fee of Rs.2 Lakhs as his fee (He says all the earlier payments were for expenses. He didnt give any receipts for my payment nor any explanation on how they were spent) based on calculation that his fee is 10% of the market value of land for whose registration he is fighting the case. He says it is the normal way of charing the fee. I paid only 4.5 lakhs for the land and now I find his demand for 2 Lakhs as the fee, even before the court hearing is putting me in a difficult situation. I asked him to provide a list of services for which I wanted to make the payment instead of linki ng to % of notional Property Value. He sent me a legal notice putting many fee components and threatened to file a case against me. Now I need to deal this person rather than my case against the realtor. Please advise on how can I respond to him. I feel charging a fee as % of property value is not correct. please clarify.