My cell-phone number started in June 2006 as a Hutch post-paid connection. In time, Hutch became Vodafone but there was no other change. In March 2016 I was forced to change from post-paid to pre-paid because of repeated trouble caused by bad administration or sheer incompetence. I then began buying Rs.500 re-charges from nearby sellers, and began to do it on-line when my bank finally issued a debit card. At some point, there was a merger of two companies and Vodafone became VodafoneIdea. Until recently, I did not have any trouble with validity. In February 2019, suddenly there was a demand for money to extend the validity - and I was forced to pay Rs.95(2 Feb 2019). I was not informed in advance of any change in the rules concerning validity.
I have recent screen captures of their web site. The first is a list of their "unlimited" offers, and the period of validity appears at lower left of the box of each different value. The next shows their "Talktime" options, from Rs.10 to Rs.5, 000. What appears at lower left of all boxes? The word "Unrestricted", which does not mean what it ordinarily does. If one clicks on "More Details" in the Rs.500 box, a small box pops up which says "Validity NA". The true meaning of "Unrestricted" and "NA" becomes clear in the text message they send concerning the recent recharge: "Congrats. Rs.500 Recharge Successful. Enjoy TT 500 for 28 days."
If the validity is 28 days, why use "Unrestricted" and "NA" at different places? This is misleading, but I am not qualified to call it cheating.