Airtel — Fastag not delivered for 3 months

I have purchased Fastag via Airtel Thanks App in Sep-2020 and it is still not delivered. I consistently waited for a month and started following up with Airtel Payments Bank support, but it is not resolved till now. I have tried all possible ways talking to Airtel and DTDC courier, but none of them acting on it. Last week Airtel executive recommended to Activate it in the App and he will initiate request on deactivating it, which he can do it only after activating it. I see in NHAI and in Airtel app FAQs that a new Tag can be issued in case of lost tags. But I am not getting any proper response from Airtel and also tired of calling their 400 number where there is no option to report issue related to Fastag. I always need to report an issue on Payments Bank and wait for their call back. This is really frustrating. Please advise.