Airtel — airtel fastag not delivered and no customer care for fastag support

I have applied for the fastag from airtel payment bank on dec 27, 2018. On dec 31, i got message that your fastag will be delivered in 6-8 days.
But i havent received it yet.
When i try to call customer care @400 there was no option to select fastag related queries and no option to talk with customer executive.
It is very frustrating and no option to know where is my fastag. They should either deliver my fastag in 2 days or refund my rs. 450