Royal Sundaram General Insurance — Cancellation of insurance not possible.

Due to a mistake from one of their agents, my car was insured twice: One from reliance(first insurer which started from 2020 till 2023) and one from royal sundaram[protected].
When I enquired about the duplicate insurance, they say renewed insurance cannot be cancelled. But their argument is completely illogical because the original insurance was with reliance which cannot be cancelled, but royal sundaram is a new policy with no history.
When I try to contact their customer care, they continuously disconnect the call after saying "pleas wait while we transfer the call to our cancellation department".
This is completely irresponsible, unprofessional behavior of these people who give themselves high ratings just to mislead people.
Despite several emails to them, they did not respond properly, and therefore I am raising this complaint in this forum.