Action against physical abuse, intimidation, misleading senior citizen by bank employee

I need guidance about what notice Or action I can take against a bank staff who has misleaded information, physically harassed my senior citizen father, given abusive customer service as well as threatened and shown intimidation by misusing his power of being a bank employee and calling police and locking bank premises gates and forcing my father who is diabetic to stay locked in bank premises till policev arrive. My father asked for a small query about a fixed certificate which physical certificate of FD he didn't receive. The bank employee asked him to do GD. My father replied he is not sure if he lost the FD certificate or even ever received it at home address or from bank branch, hence why will he do GD. He even replied if the bank did despatch the FD certificatein time, it could be a mistake from bank's side as well. And he asked bank employee to give in written that he has to do GD for getting the original FD certificate or even duplicate certificate. My father did not receive the original FD certificate which was just issued on January, 2021. And he was advised to write a letter for duplicate FD certificate and now extra demand was to do a GD for getting duplicate FD certificate. My father was refused the advise of doing GD on paper in written by the bank officer after he requested 7times. Finally dad said lost his cool and said are you doing this job seriously or simply casually. In return this officer made the peon physically manhandle my aged father, locked the bank gates and didnot let him go. My dad said he is diabetic and they can send police to home address if needed but let him go. Later the police came, my dad said check cctv if he has done anything wrong or misbehaved. Police didn't harass or ask dad anything after that. But this bank employee simply went back to his desk. I want to take some action against this bank employee as he will always misuse bank's power to call police, harasss customers or senior citizen n forcibly keep them locked during customer hours and manhandle them via peon. This is sbi bank. And as far as I know during customer hours, how can a customer be forced to stay locked in bank premises. Is my dad a terrorist. If he had a heart attack or there was a fire or burglary attack at that moment in bank, who would take responsibility of me, my family and my dad's life. I will complaint to bank on each platform possible but I also want advise from a lawyer on what action I can take against this sbi bank employee about his misleading information about FD query, abusive and intimidating customer service and behaviour and physical manghandling of my dad who is senior citizen. All cctv footage is there of bank about this incident. Kindly help me to take action against this bank staff as for each future visit to this branch, we need to go with our heads high. I beg helpful responses and suggestions please.