BSNL Broadband becomes slow during daytime

BSNL broadband works like a breeze at night especially after 9 PM. But during daytime I don't understand what happens that some sites work okay, while some other sites become very very slow. For example until a few days ago, during daytime Youtube would work fine and I could easily stream videos at 480p on my 4 mbps connection, while took forever to buffer videos even at 200p on some other video streaming sites. However since a couple of days things have become just opposite. Now other sites work fine, but Youtube suffers. I'm able to stream videos only at 144p on Youtube on my 4 mbps connection. At night everything works great.
Is there anything I can do to resolve this issue ?

There is nothing on your hands. Talk to someone at exchange.

I think BSNL has too many customers than their servers can handle now. That's why during night time, when less people are using the internet, you get good speeds. I know exactly what you are saying. Before I could surf the internet nicely without any problems in the morning but now since past 1 and half year the connection in the morning is really bad. Especially after 10AM - 6:30PM which are usually office hours.

Morning is peak hours , so it is expected to be like that. but not to very high level where you cant even browse.

In certain areas their lines are certainly congested and affect the traffic.

You can browse, but only plain HTML sites. Rich Internet Content performance is simply pathetic between 12 Noon and 6 PM. I have a 4 Mbps connection and Youtube videos can play smoothly only at 144p. I've heard many people play videos at 360p on even a 512 kbps connection.

It depends on users secondly stop unwanted services and apps in ur pc/lappy inorder to get more speed.