Customer service rep

C: Woman says, “what is the reason for your return.”
T: None of your business, return it; I’m not interested in helping your marketing department.
F: Annoyed
A: Speak in short, direct sentences, I tell her exactly why I want the return, feel the tension in my body, write in to ask a coach, think that I shouldn’t be acting this way, judge myself for being such a b*tch
R: Well, I actually told her exactly why I want to return the product even though I thought I don’t want to help her at all, which doesn’t make much sense!!!

This is kind of strange and funny! I guess I can start with the understanding that when I think “none of your business,” I feel annoyed, so it’s normal that I would feel annoyed in this circumstance.

Any other tips for dealing with customer service people?