Health Insurance claim rejected due to late claim submission

Hello Sir/Madam, I had oriental health insurance for my father who died on 15 July 2022 hospitalization and related claim (discharged on 09 July 2022) submitted in insurance company on 12 Sept 2022 after approx 70-75 days because of occupancy in ritual pertaining to dealth as well as misinformation that it can be submitted after post hospitalization period i.e. 60 days, after submission of claim queries were raised and satisfactory reply given in due course of time. As of now claim rejected just because delayed submission of claim, even after several requests to Branch Manager delay condone was not approved by concerned authority of insurance company. Is there any way to get the reimbursement of claim amount from insurance company? Please provide your valuable advice with necessary process to be adopted for the same Thanks,