Its very expensive to use a bsnl sim card as the data packs are very expensive and call rate is also not fair.
The main reason why I dont like it is because of the sim validity extension, after every four to five months the validity of sim is to be incerased at the rate of 33 rupees and this is not happening in any other company. Services are also not good and data packs are more expensive and many times network is not available.