HDFC Bank Fastag — i have reference no. hfr474548 but nothing get except this, no email and updates

I have applied for hdfc fastag on 23rd november and i got above mentioned reference no. Hfr474548 but they didn't send any emails or updates regarding this. No call attended by hdfc fastag helpline number. Please solve this issue. I didn't get any information about my application and hdfc fastag didn't provide any facilities to check our application status via reference number. This facility should be provided