"RBI had eased out rules of deceased claims in 2015 , specifically asking banks not to demand succession certificate or any special document in case of intstate death for no nomination account holders....But few govt banks are still following their age old policies , solely due to lethargy towards changing policies at par with RBI guidelines"
You have the option to take up the matters with the Banking Ombudsman. Prior to that it is better a complaint is made with the internal grievave refressal portal of the concerned Bank. It serves no purpose to indulge in verbal duel with the local officials.
The grevance with the Bank as well the Ombudsman could be taken up online.