There is alot of things to write about this Telecom company named as BSNL.
Pros
Network avaibility is super even in village, it covered all Rail & highway.
Price and billing is accurate total transparency no auto deduct of balance.
No call from company about their new product launch, they choose sms for it.
Cons.
Pathetic customer care, lack of knowledge about their own service they provide. They even don't give you complaint id if u ask for.
Network fail maximum time.
They do less advertisement in television about their product.
They don't have 4G service till now even they have won it before the private company like airtel aircel etc.