420 case

one of our known person asked for loan for his buisness he assured us that he will pay it back after a month and he pleased us for buy a car on #emi in our name and we trusted him blindly we never used that car but we pay rs.12500 to company as emi and margin money also and he also asked us for a agreement (affidawit) which is about transfer of ownership but we asked him why it is written here that you had paid us all the amount of car then he replied that its just for a shorter period time as my financial situation will be fine i will change this document he pleased us and we got agree and now he has changed and saying that he has the papers and we can't do anything and main point is that he has maded the document without the registration no. of car
please give some advice