HDFC Bank — new fastag is blacklisted

I ordered a new fastag from hdfc online portal. It got delivered to my home. I pasted it and when i tried to pass the toll it showed blacklisted tag.
I had to pay up double fee to pass that toll and then again for the subsequent tolls i had to get in the cash line.
My balance when i received the fastag was rs300 and then i recharged to for 100 to make it rs400.
I tried calling the helpline number for more than 100 times and after 150th call somebody picked up only to tell me that he is having portal issue and won't be able to help me.
I called the hdfc bank customer care as i'm a customer but to my surprise they said that they don't have any info on this and i need to call fastag support.
I repeated the same 100 time calling procedure and after an hour a lady picked up and told me that my fastag was blacklisted but she was not sure why. She told me that she is putting a request to remove it from blacklist and it may take 24-48 hours. I have been calling constantly to check on this but hdfc's fastag support system is immensely poor. I am not even able to put a call today.
I request the hdfc bank to provide a clarity on this and provide a solution asap.