Airtel — esim mobile data service

My mobile data is not working since 8th march afternoon after i received this text “alert! You will not able to use to use data services on your existing sim. Upgrade to free 4g data sim now to enjoy internet services. Contact your nearest airtel store or retailer”

I’m using an iphone xs max and have airtel esim with which i’m using 4g since past one nonth. I have tried turning on and off the phone switching the line on and off but no luck.

Called airtel customer care on 8th march evening they said we will resolve the issue but no luck.

Complained with a senior customer care agent on 9th march she said restart after four hours as she has refreshed setting from their side still nothing is working.