If they are unable to handle things like this on the phone, they shouldn't provide a phone number to call for more information and instead, provide an office address to go in person to speak with someone.
The problem with that is, they have downsized the physical spaces to only things that can provide them with profit. Giving customers a place to lodge formal disputes doesn't meet that definition. That's why they leave the only the number to a call center in India.
When dealing with banks, especially with something as serious as this, ALL of my dealings with them are in writing. If I must go to court there will be no "he said she said" bullshit.