Airtel — sim not reading after porting

I ported my number from Vodafone to Airtel, last night Vodafone got deactivated so i inserted new Airtel sim but it's not being read by the phone so I'm not able to activate it by calling on the given activation number.
Please help.
I called the Airtel helpline and they told me I will be getting another message telling me that now the sim is activated. I believe this is wrong, since my old sim is now deactivated, my new sim should get activated almost immediately and not take another 3 days time.
Has anyone else faced the same problem? Whats the resolution to this?

Attached is the communication from Airtel asking me to insert sim and activate. Got this yesterday (19th June) and Today (20th June, 2019).