Fruad by Developer in Sale of Plot

Dear Sir, Around 10 years back a land developer showed me a plot plan in his office and accordingly I finalized a plot in outskirt of Patna and finalized the cost along with registration & mutation and paid the advance. Developer asked few month time but after followup of around 2 years he finally agreed to do the registration of sale deed but he changed my selection of plot and also added 80,000 more so in fact it was a two way loos but we have not signed the agreement thus I agreed and paid him balance amount with addition 80,000. He did the registration of sale deed and we go the paper, after that we asked him mutation paper and he was always keep on dragging time. Finally after 4 years he told me that plot is having issue and mutation is not possible and presently he is fighting in court for the possession of plot. We asked him to show us court paper so that we can think for settlement but never did so. We asked for another plot but again instead of 1500 Sq Feet plot he was showing 1200 Sq Ft plot in very interior location with thinking that he has taken the money and can put us down the way he want. We didn't agreed for the same. We checked with Govt. land record office and came to know that the plot he registered to us belongs to Govt. as per record. Please advice what to do in this matter as if I will go for refund with 10%, land cost appreciation is much much higher than the amount now. He did cheating multiple time to us and now it is proven that with Govt also. Your suggestion in this regard will be very helpful.