I have never followed up on such calls i.e. never cross questioned them to figure out if they are genuine, but I find it odd that NGOs (if this is indeed not a racket) have started calling up people randomly from some phone list that they have acquired. And I have never heard of the name of the NGO (it is not the familiar CRY or Helpage).
Is this a new form of "you have won $1000,000 from our lucky draw/I am from Africa and am inheriting $2bn"?