That was pitiful. Why would she want to keep doing business with that bank after the poor experiences previously and now? Noble or commoner, she should take her business (and money) elsewhere if she feels she's being treated disrespectfully and inappropriately. By throwing her faux nobility weight around, she will only gain equally faux respect.
It's a big city, so there's no way that would be the only bank around. Plus it's not even some exclusive nobles-only bank, which you'd need to use if you don't want to be mocked by other nobles, because she was taken to the commoners' waiting room. I just don't get it. It's like she wants to punish that particular bank and show them who's the boss now. It's utterly pointless. The relationship between the bank and her will always remain strained, so it would be much better to switch to another bank and start with a clean slate. There ought to be one bank in the city that would see beyond her old reputation, especially when her first act is to deposit money, not ask for a loan.