Bharat Sanchar Nigam [BSNL] — my landline is down for last 1 month

Address:

Bangalore, Karnataka, 560066

Hi, my internet is not working for last 2 month, for last 1 month its completely down. I tried calling the support guys unfortunately no one is responding. Even i tried to register via online, but it says my "my landline details are incorrect". I pay all my charges via bsnl portal and the same portal is not allowing to raise a complaint. Also when i took the connection they promised me a modem with power backup, unfortunately from the day 1, i haven't got the battery. Not sure how to sort this out.