Tata AIG Insurance — Unjustified Denial of NCB Certificate

I have a TATA AIG car insurance policy no. [protected] 02 in my name i.e. Man Mohan Sharma which is for my car having registration no. DL-2F-HW-0077.
I am buying a new car Honda Amaze. I have made a written request dated 18.02.2021 for issue of NCB certificate, however one Vijay Bisht, an official of TATA AIG has orally refused to issue such certificate stating that it can be issued only when the old vehicle is sold.
Such stand of TATA AIG is legally wrong.
NCB is a right of the policy holder and does not vest in the car. The oral denial by TATA AIG official is against the law and against the rules of IRDA.
The acts and omissions of the of TATA AIG official are not only against the law, the same is depriving me in getting the delivery of my new car for which I have already paid the full price.