Airtel — Airtel international roaming failed completely in the USA

I am extremely disappointed and frustrated with the way this issue is being handled.
I am currently in the USA, and my Airtel postpaid international roaming service, which was working perfectly for the first seven days of my trip, suddenly stopped working without any prior notification or explanation.

Despite having an active international roaming pack, I have completely lost access to mobile network services. I cannot make or receive calls, send or receive SMS messages, or use mobile data. My phone continuously displays "Emergency Calls Only."
I have already performed all the troubleshooting steps suggested.

I have also contacted your support team and received only a generic acknowledgement. That response is not acceptable.

Being left without mobile service in a foreign country is a serious issue