I’m using telenor network from last 3 years and what I think about is that if you are at good location i.e at good height, near city, not at ground floor of a multistory building then u would get a usable or say good tower network in your mobile but if you are not at any of such place it would be hard for you to get even a single tower in your mobile for calling. Now talking about billings and recharge price I would say it’s best for calling plans. At present I use a plan of RS 94 of unlimited calling std and local both for 28days and 1GB data. But one thing is that u won’t get good network for browsing or any other internet activity.
Making conclusion I would say if you are at a good location I.e in close to city, not at below of 4/5 floor of a multistory building. Then u can use this network for calling.