About Network : I am using this operator minimum before 6 year around this operator service is superfast and Network are very Good you are go anywhere aroud india but your network show full network not vanished you have lot network option like 2g, 3g and latest 4G so you are talking continue.
About customer service : these operator are customer service is very good if you have any problem so you call customer then he was take your call only 2-4 ring and your problem solving on spot so this good.
About charges And Billing: it is provide you long range of service plans you can buy which you want.
thank you.