Recovery of charges and witholding information by banks and not apssing account information to survivor

Greetings, My father passed away three years ago due to cancer. As the only surviving child, I was unable to follow up consistently with the bank to close his account while continuing my education and managing family responsibilities. After my father's death, I informed the bank about his passing, but being unaware of the banking procedures at the time, I didn’t ask for the account closure forms. My mother is uneducated, and I had no idea about the necessary steps to take after his death. My father had an account with Saraswat Bank, and we were expecting dividends and payments from his business associates for goods sold. I informed the branch manager of this, and she advised me that the account could be frozen unless I purchased an insurance annuity product from the bank to keep it active. Now that I am trying to close the account, the bank is demanding payment of non-maintenance charges from me. When I ask for details about any fixed deposits or other assets linked to my father’s account, they refuse to provide the information. They are also unwilling to close the account unless I pay the charges. Additionally, they are denying access to account statements or passbook details. I am currently in a difficult financial position, with both a student loan and a home loan post my dads death that I am repaying. I am unable to pay these charges. The bank is threatening that the account will become a defaulter account, causing further stress. I am a young, single individual supporting my mother, and I cannot visit the bank daily due to work commitments. I have informed them that they cannot recover these charges from me, but they remain uncooperative. What are my options in this situation? What banking rules or guidelines should I be aware of so I can escalate this matter and keep records for future reference?