Call centre staff member rude and unhelpful

I have been with Nedbank for a few years and am most likely upgrading to Professional Banking next year. The website and functionality is fantastic, but my interaction with the Investments call centre yesterday was awful.

I called in just after 5pm to query a tax certificate for a Tax Free Savings Account that I closed a few years ago. My tax certificate for the Account stated I receive interest in the past tax year, despite the start and ending balanced being R0. The Investments call centre agent was rude, saying "why are you phoning in if you don't even know which account it is", because I have her both my main account number and the TFSA account number. When I asked to speak to the manager, I had to wait so long that my airtime ran out and I had to quit the call.

I do enjoy banking with Nedbank, but experiences like this make me consider changing banks.