Mother document changed

I have bought 25 cents of land from a seller with the mother document 700/2002.  Later i came to know that the correct mother document is 340/2003 only. we didnt noticed this during registration. Now i consulted the document writer, they advised to register new document only instead of rectfication deed because of different mother document. Now i approached the seller to come for registration, but the seller demands more money. Now where should i complain? it is like cheating...