Airtel — no network and hopeless internet speed

Address:

Bangalore, Karnataka, 560017

I am an airtel customer for the past 9 years. Currently residing in bangalore. But sad to say, airtel has become one of the worst services one can get. Most of the time, i use my portable wifi to make a call through whatsapp. I do not receive calls when in office. Every day, i have a fight with boss on non connectivity. My boss too calls me over whatsapp these days.
The problem is like this: most of the time, i do not receive calls even though phone shows network. When i try calling from another number to my number, it says my number is not reachable. When i try an out going call from my number to any other number, the network suddenly drops and the phone shows "no network" or "emergency calls only". This happens in bangalore and chennai. Fed up of the service.