I have started using BSNL SIM for five years. Though the company release Good plans . But networking not everywhere . In most places emergency call are only visible. If the network problem is reported to the customer care They do not accept any action.
this is my experience Last month I recharge net offer for 1 month. after the recharge offer become active. I turned on the internet service. But do not get an internet connection. I called the customer care. Lodged a complaint but no action. I do not reveal the name of the customer care officer( he is from kerala). When I was told that I intend to change my company. But they said. you will do what you want. the call was cut. very bad service