Rejection of personal accident insurance claim

My father had a Kotak Bank Savings account with which he was given a VISA debit card. The bank claims that its debit card has Group Personal Accident Insurance cover of Rs.5 lacs. My father died in an unfortunate accident on 22nd May,2022 by falling through lift shaft. The bank is now saying that its Group Personal Accident Insurance covers rail and road accident only. The Insurance company providing this insurance cover is United India Insurance company. The insurance company accepted that this policy does not provides the regular features of Personal Accident Insurance policy but it adds the exemptions in the terms of the policy were done on the request of Kotak Bank. Whereas Kotak bank denies requesting the insurance company claim that it requested the insurance company to tweak terms and coverage of the policy. Although both Kotak bank and UIIC claim that the insurance policy has been approved by IRDAI, IRDAI in its email sent to me denied giving permission to any such policy. But at the same time, IRDAI says it does not have the right to take action against UIIC. What should I do now?