Cheated me selling land where survey No does not exist

Hi Sir/Madam, I am Krishna From Hyderabad, i have bought a land of 200 yards in 2018 for 1000000, investment purpose, so i left it until 2022, as i was in financial crisis due to loss in business i kept it for sale, and got a buyer at the time of agreement examined all link documents and said that this land is not clear and the problem is survey no does not exist and sold the land to other party as well. i was shocked and gathered all the information. I approached the person who sold the land to me and proved that survey no does not exist and sold to others as well initially he denied but after showing all proofs he agreed and gave option that he will give other land but i insisted to take back that land and to pay as of the current market prices but he said he will be taking back that property for 1500000/- (Market Value 2000000) in 2022. as i was financially in bad position i agreed on condition that total payment should be done in 1 month, but dint do any agreement and he paid 500000/- cheque, after 1 month he said am arranging money till then he sent another 200000/-, next he dragged it for another 2 months and paid 50000, 20000 small amount and i received 785000/- from dec 2022 he stopped giving reply and was absconded. Last week he called me and now he is asking to do registration for the same agreed amount 1500000/-. Need help 1) What should i Do. 2) Can i demand current market value? 3) am i compelled to do the resitration for the amount agreed in 2022. 3) He got good name in that area am planning to take it to media regarding his cheating almost 20 plots. please suggest me what to do now.