Westbank agent : "stop F%$king shouting at me"

I settled my finance on 1 August. Westbank never closed the account, so now I've accrued interest on the account and its still open. I called the service desk, and was told I need to call an 0860 number. I've moved to New Zealand - when I explained that I can't dial an 0860 number, the agent told me to her. (I'm calling from a laptop, trying to use skype) She then said she was going to find the 021 number and put the phone down on me. This is unacceptable. I settled my finance, and westbank didnt close the account.