My advice to anybody who pays out advance/down payment to a private person (who cannot give you a printed receipt) is....

get a copy of his ID card (which is not expired), and let him write on the same page that he has received XYZ QR, for so- and- so purpose, and let him sign it..make sure the signature is same as that on his ID card..this makes sure u are on the safe side..

the reason for the down payment should be mentioned, as else he will claim it was a loan,and he paid it back in cash..

and of course this does not help you if he leave sthe country..