BSNL Dataone Connection

One of my friend Andrew is in big trouble. He waited for six month for BSNL Dataone connection. He got his connection in December. And the bill came about Rs 3500/-. Bill contain Rs 1200/- for modem. Rs 180/- telephone rent and Rs 500/- for Dataone. But the problem he is facing is that the extra usage of Datone but he got on 25th of December. How can he use 2.5 GB above.

So now he decided not to pay the bill for connection. But the net connection is still working. He had not payed bill for past two months. And he is still working on net without paying. So he is lucky to have free internet connection. But the main problem is that if he is not using the internet. How can the long bill comes. Only he and the guy came to install modem knowns password. So the guy how came to install modem can use the internet for free of cost.And the guy came to install the modem has told that we cannot change your password. So it is very unfair with my friend. he also complain in the BSNL office but no one is listing to him and saying we doesn’t have any track system. So we can find the person who using the net connection. So in your opinion what he should do. Please give useful comments.