HDFC Bank — fastag applied from hdfc bank, no confirmation no progress and not able to reach the number provided

Address:

560066

I have applied for the Fastag from HDFC and paid 500 INR om 15th of Nov'19. I have got the booking reference number HFR382758. The booking reference stated that I will get an email but I did not receive anything plus it said that a representative will get in touch with me very soon but so far no one have reached me yet. They have given a toll free number[protected] which seems to be always busy or just not getting connected. (*Not really sure if they intend to keep it busy always)

They have promised that I will receive the Fastag within 7 days, but its already 6th day, not even an email confirmation of the application that I made along with 500 Rs.

Could any one help me here with any sort of lead to complete this process.