Cashless hospitalization rejected - Narayana Health not in network list

I have a health insurance policy from ICICI Lombard with sum insured of 10 lakhs. Last week, my husband had to be admitted to Narayana Health in Hyderabad for dengue fever. When we tried to get cashless treatment, the hospital said Narayana Health is not in the network list of ICICI Lombard. But when I bought the policy, the agent told me that Narayana Health is covered. Now I had to pay 7 lakhs from my pocket and I am trying to get reimbursement. Has anyone faced this issue? What should I do? Can I file a complaint somewhere? The TPA is also not responding properly to my calls.