I’ve disputed fraud a couple of times on my Chase cards. It was.. fine? Uneventful and simple.
I guess I'm lucky they rejected me before any money changed hands. I've heard horror stories from people with significant assets at their bank, locked out until an actual lawsuit (the letter from a lawyer didn't work) finally got their attention. I think it's like Google support, usually fine but catastrophic when it's not.
As far as I can tell, going to a branch of a big bank to address a problem nowadays is similar to going to a cellphone store for tech support. All they can really do is call the same hotline or fill out the same webform you’d have access to at home.