I was telling this to my boyfriend and it made him laugh.
A sales person is pressuring me to buy. I keep saying "no." Then I finally snap at her and she says "You don't need to be rude."
I say, "Well what do you expect, you keep harassing me to buy something and I have told you "no" a few times. Do you not understand the word 'no?' Even a one year old knows what that word means, you should too because you're smarter than a baby."
(No this didn't actually happened, I was just telling it as an example about me I should start getting aggressive with them)
Oh yeah maybe I should add this insult "Or are you not smarter than a one year old since you don't seem to understand what 'no' means. I'm surprised you can walk and talk and have the ability to pester people to buy. Very smart for a retard with a IQ below 25."
That might show them.