Seller did not give documents of the registration of property

I have purchased a shop in a building in the year 2004 for Rs.2 Lacs.An registered agreement for sale was made in the same year.The possession of the shop has been given in 2010 and presently I am running my business from the shop for the past 7 years.Due to some financial problems at that time I could not register the shop in my name.When I approached the landlord for the registration,he said that he cannot give the documents required for registration.I would like to mention that the amount was paid in installments.But out of Rs.2 Lacs,I have got receipts for only Rs.1.15 Lacs as the remaining amount was paid without receipt on the basis of good faith.I have send him a legal notice about a year ago.But he has not replied yet.If I file a case against the landlord will he be able to demand the amount for which I do not have any receipt?Also I want to know whether he can resale it without my knowledge?