Airtel is the most reliable and the most expensive network in india.
you will have to pay extra considering other networks but it is well worth it.
the connectivity is just awsome even when you are traveling like in train or bus.
So you can justify the price with the quality of the service.
the costumer care is great 22*7 and the time they take to clear any issue is just minutes.
there were many times that I had lost my main balance even when there was internet balance. all the time I got my balance back by conatcting customer care