With JIO Prime and unlimited daily internet, most other providers have come up with similar plans for prepaid. While JIO unconditionally gives the plan for new and existing customers, some other providers have some catches. Looks like Airtel and IDEA too have similar plans for new and existing users. So currently (as of 3/27/2017) is Vodafone the only provider who does not provide this offer for existing customers? I do remember that vodafone had announced a similar offer with an end date of March 15, but myself or none of the people I know of has got the offer.

When you install watsapp on a new phone, it will ask for re-verification in the old mobile. I assume this is a security feature. 

I re-verified using another number put on the phone, but could still access other persons messages. Interestingly I could also send a watsapp message to myself.

So I am checking with watsapp whether this is a bug or an expected feature. 

Will update the response here.

From my experience, which I am going to share, IDEA is one of the worst service providers in my state. Issues start with connection activation, bill changes and above all, the way customer care people talk to you. When you have better providers like Airtel, Vodafone and the new entrant Jio, who all have a better customer care and services, I don't see any reason for going to IDEA. I did the mistake just because they said they will give a good looking number for free (free of charges, but not free from head aches).

This is the experience of one of the airtel postpaid customers who had received a mail from Airtel CEO regarding a surprise offer.

To counter Jio, vodafone has posted ads for unlimited calls with 1 GB data per day for 1 year with 342 recharge of 56 day validity. There is also another recharge of 346 with 10GB data per month and unlimited calls. Pic from a shop wall in Marathahalli taken on 11/3/2017 attached. It also says that it has to be done before 15th March.