Airtel — Airtel broadband connectivity issue

I am facing Airtel internet intermittent issue every month since 6 months.
complained many time and they are providing temporary solutions.
Issue started 27th 2022 at 6PM till today 28th 1 PM there is no acknowledge on the issue and no is responding by email, customer care and even twitter.
I have sent 10 emails to nodal.[protected]@in.airtel.com but there is no responses.

I want to put case against on Airtel behaviour and service issue.

Could you please guide me how and where to proceed