Is Airtel still giving 28 days validity if we recharge for Rs 100?
EDIT: I just took a chance and recharged with Rs 100 as I had AmazonPay Prime offer "Collect" - 50% Cashback up to Rs 40, valid only on Airtel Prepaid.
So effectively, paid Rs 60 from AmazonPay Balance, got Rs 81.75 talktime as well, and a validity of 28 days.
I was on the 90th day of my Grace Period, so needed to do a "usage/activity" to retain my number and not let Rs 20 get deducted by the "automatic number retention" scheme as per airtel / TRAI Guidelines.