I am just utterly blown away by how many people have family members who try to manipulate their name choice by saying they will refuse to use the name.
I mean, seriously, WTF?!?! That is a SERIOUS case of entitlement!
Why do they think they get to do that? I bet they'd never say to a boss or a friend or a employee, "Hmmmm, I don't like your name, so I'm going to call you James instead."
I'd be so tempted to tell them, "Okay, cool. In fact, it's quite a good idea. I've never really liked your name, so from now on, I'm going to call you Fuckface." Then I would do it till they broke.
Can you imagine having that conversation with your child?
"Mummy, why does Grandma call me Anna when everyone else calls me Sienna?"
"Well, darling, Grandma thinks your name is ugly so she decided to use a different one."