This is really a mystery which is not yet solved !!! If you verify your phone, you will find Toll free number 1800-300-1947 stored in the contact list of your mobile phone .
Amazingly you have not added this number and UIDAI has made it clear that this number doesn’t belong to them.
UIDAI said in a Twitter response that “18003001947 is not a valid UIDAI Toll free number where as Press Bureau of India showing this number as official toll free number for Aadhar Grievances.Check the PIB letter
This toll free number was stored on the smartphone regardless of whether you had linked your Aadhaar or not, or even had an Aadhaar number in the first place.
Do you really think that this is done for malingering the image of Aadhaar ?