1. Go to data.bsnl.in, My orders, enter your telephone no in the prescribed format and hit search. Check for the order status and effective date. Check order status is provisioned or not.
2. Only data that comes under excluding night will be charged.
3. To get night unlimited, you need to reboot your modem a little after 2.00 am and a little before 8.00 am. You need not be awake to do the process. There are tools using which you can automate the process.