Airtel — I'm complaining about call quality

Address: Chandigarh, sector 12, PGIMER

Since last few days, during making or receiving calls, voice is constantly breaking which makes it unable for me to communicate via mobile phone on daily basis.
My only option is to make calls using wattsapp, which is againis not convenient everytime.

Mind you, my microphone and speaker are perfectly functional.
To make it worse, airteldoesnot have customer chat support or email id whete I can file a complaint.