Vodafone India — charging on aadhaar linking

As per government rule it is mandatory to link our aadhaar card to mobile number, and also i was keep getting reminders from vodafone for same stating to visit yash communication, india gate, sitapura, jaipur (Image attached) for same but as per my personal experience they are charging us rs.10/- per head as processing fees. Vodafone should have mentioned about fee if they are suggesting about store.
I went to same store, thursday that is 07/09/17 at about 07.00 pm for getting my phone account linked with aadhar. The person (Babu lal meena image attached) on duty asked me rs 10/- (Ten), for linking and rs 20/- for 4g sim exchange. He demanded money after linking and exchange process, when i demanded a receipt he replied rudely that “no receipt will be given, you will have to pay for it”. After too much argument, of course i had to pay, but so many innocent people are going there. They are all at risk. Why should i pay money for this? Is it legitimate? If i should pay then why did not i get any message for this from vodafone.
Though it is free of charge how can they charge fees to us. Kindly look into this matter asap.