Update:
I just called HDFC customer care. Thanks to everyone for all their recommendation and suggestions. Not possible to include every commentators name in this post but, everyone helped me get this sorted.
Initially, they denied, After that I followed you guys recommendation and said following points:
1. as
@D₹V said, I said that there was issue in HDFC URL and I will escalate this much beyond you guys can think.
2. as
@prmuch said, I told them about the RBI circular and said I will escalate this to redressal and RBI eventually, and then they put my call on hold and after 2 minutes said that there is a cooling period of 7 days and for you, 3 days have passed so if you again maintain balance back in the account and raise the cancel request, bank will be able to proceed with Cancellation.
I took another 10 minutes of time, maintained the required balance, and called them again, sadly had to explain all the situations again including above points 1 & 2, and she finally raised a cancellation request and said that the loan would be closed by 2nd November.
Once again, Thanks a lot everyone for saving me from this financial blunder.
I will post another update by the 2nd or 3rd of November to let you guys know the update.