Idea Cellular — idea sim showing no service in my android phone

My idea number which i was using from past 3 years suddenly shows no service/emergency calls only.
I removed the sim from slot and placed in another phone and the result was same and i also placed another working sim in my phone to check either the issue was with my phone or sim and the other sim which was from idea was working in my phone in both slots. I did everything but unable to know the exact reason of sim unavailability.
My sim belongs to andhra and currently i am working in mysore and there is no possibility of contacting the customer care office due to covid-19.
For your information my phone did not fall/no water did not went inside. It was working fine untill now.

I tried to call customer care but i did not get the valid answer from them. Kindly look into this issue