Airtel — airtel sim not working, cannot call or send msg to 121 or 198

Address:

Mumbai

Today got call from airtel, and they asked me to send stop to 121 by sms! But when my sim itself is not working, how can i send sms. I am trying to call back, but the number is coming busy.

On 21 st april 2020, while my working sim was still in my phone, early morning, the sim is not getting recognised. My mobile prepaid number is [protected]. As a result all my outgoing and incoming calls and data cannot access. I am not getting my bank otp etc..
As a result cannot call 121 or 198 or msg. Tried calling through other phone, but then there is no option to speak to customer care executive.
Kindly look into the matter urgently.
Even emails are getting auto reply.
I don't understand what is the reason. Please help