Civil and Cheating case regarding property(land)

Good Morning, I have one question that, land owner after taking above 20 lacs (some amount by cash and some amount by deposit) executed sale agreement in 2 pages and also executed 1 Receipt then I asked to the owner to come for registration and the remaining balance I will pay u at the registration so I requested to the owner many times but not yet came for regd. so I issue the notice and then lodge the complaint then after I came to know that the owner already taken the mortigage and also that document is regd. without possession to the mortigator, so we file cheating case on the owner name. Now my questions are that 1) Is the sale agreement has to execute more than 2 pages? 2) The owner is the sole person then is the legal heirs will come under the name of her, if the owner passed away? 3) The cheating case will be applicable in this matter as the date of our agreement is in the month of Feb and the Mortigator is in the Month of Jan? Kindly help me and do the needful with your suggestion. Thanking you, Regards, Srivalli +91- 7207784571