Airtel — wrong information given while giving broadband connection

Address:

Bangalore, Karnataka, 560040

Recently took broadband connection, airtel agents told we will get 40mbps speed but i'm getting only 16mbps in our area. They are not picking the call also. My registered number is [protected].
I have lost my peace by calling them again and again need compensation.
I need more speed for my official work if airtel is not providing we will go to some other network. I want to hear from you at the earliest