MTNL
Broadband speed is too low and connection getting disconnect again and again

I am using MTNL BROADBAND CONNECTION (TELEPHONE Number: 27894050) with 256kbps unlimited plan and i am getting the speed is around 150kbps and the connection keeps on disconnecting and since last two days i am trying to download a 10 MB file and failed so many times.

The service is all time worse.