Cancellation of Agreement

Dear Sir/Madam, we 3 siblings have x acres of land in telangana area which we got it from tenant act and having pattedar passbooks, latest pahanis and 1B certificates in our names. we thought of selling that land and in February 2015 we have signed an agreement with one party by taking some advance as token amount where the party promised us that the land will be converted into plots and we have to register in due course of time to plot buyers and in the agreement its mentioned that they are giving advance amount and rest will be given at the time of registration. they had cleaned the land and made it into plots with roads and all, now they had changed the mind and saying that want to withdraw and asking us to pay the advance amount and the amount which they had incurred in making the land into plots which is 3 times the advance amount. we dont have any money to repay them. my questions would be. 1. Is it mandotary to pay the advance amount back with the charges they are asking for to cancel the agreement and sell it to another party? 2. AS we said we cannot give money back they are asking for PDC's or sign on a promisary note. please advise. 3.basis the agreement can they go to court of law? 4 Please help advise to get out of this legally and sell it to other party. 5. will it smooth to sell the land with complete amount and register or give it to a party who can make plots and sell and we register to the plot buyers. please advise. Thanks & Regards, Krishna