@deepanshu7 Your LCO is a scamming cheapskate.
I had my connection through an LCO. I was paying for the 150mbps plan. I got the full speed, even more, in the first month. But after that I was limited to 100mbps both download and upload. I'll spare you the story, the guy was limiting my speed to 100. After a lot of going back and forth with BSNL, finally called this guy and he had the guts to ask me if I really needed 150mbps.
I told him yes but nothing changed. Mind you this guy also did connections for Asianet and Kerala Vision broadband as well, and for a long time has been trying to convince us to switch. Finally complained to BSNL that he did it, the guys came took off his fiber said it was a common thing among these people.
BSNL was pulling fiber straight from their office through our area that time, we switched to that.
Remember your LCO might get more commission if they can get you to switch to another ISP they partner with. They also save on equipment costs. Not giving you your full speed, they can use that bandwidth to add more connections without upgrading.
Complaint to BSNL as soon as possible.