Airtel — no signal on airtel sim

Address:

Indirapuram, Ghaziabad

Hi,
One of my airtel sim is not showing any signal since last friday. I've tried to call 121 from my other airtel number but there is no option to contact customer care. I tried using airtel thanks app but it asks for otp. Now since there is no network i'm not getting any messages. How am i supposed to enter otp? This is weird how one of my sim is working but not the other. I've tried swapping, inserted the sim in another phone, troubleshooting, and everything but nothing works. Please resolve this as it is my main number.
Note: i have both my cell numbers recharged with the same pack.