Seller is NOT willing to register after Agreement (Unregistered)

We have made Agreement to buy Agriculture and this land owner had already had agreement with another financier which was registered for grace period (2 years) for him . We got into tri-party agreement between Us & Seller and also Financier agreeing for same with witness ( we got into Unregistered Agreement since already they was agreement between financier & Seller, they told they will cancel that previous agreement before executing the new registration during our final settlement) and all three parties have signed on this agreement and the agreement validity was for 4 months. Now after 2 months have past, Now the financier is claiming that he would return our Advance money back as part of the agreement which we paid since he found NEW Buyer who is willing to pay more. Though last 1 month we are following with them to register the land, they have giving some excuses and now the story is totally different where they want to return our Advance money with minimum bank interest. In fact, I am keen to complete the registration even in next 10 days but with this new twist . I am not sure what options I have in front of me with this Unregistered Agreement. Please do Advice..