Regarding claim on bank deposit

My father died in 2015. He was a teacher in ZP. He had some amount of money in JDCC bank as a salaried account. We have a valid death certificate. A family certificate from tahasildar. A legal hair certificate and the main A succession certificate from the court which clearly mentions the exact sum of money in that bank account.. To be given to my mother me and my sister.! When we went to claim the sum of money the bank manager refused to accept the succession certificate and said.. You would req. A letter from BDO. That we are legal heir of my father..! And when we went to take that certificate BDO told us that and I quote "we don't give letters anymore that system is closed now. No need of letters". I am astonished to see how people can misuse their power..!! Plz help me. What can I do...to claim my father's money. Which is rightfully ours..!!  I m a Buddhist.