I'm not sure I agree with marvellous on this.
A person's preferred name is not a trivial thing. To the outside world, a name is part of someone's identity. Getting it right is important.
Exactly. I suppose it could be phonetically correct to spell my name Beonka (Bianca), but that's not my name, and I would definitely address it in a timely fashion.
It used to mildly irk my father that his own brother would spell his name wrong. Or I should say that the way his brother spelled it is a valid spelling of the name, just not the right one. (Ie Stephen instead of Steven)
My son's having trouble with kids at school who keep misprouncing his surname on purpose. DH's surname is one that, if two letters are switched, it is spelled the same as a tropical fruit. Let' say our surname is Gauva, and people are always wanting to say Guava. DH keeps telling him to get used to it, it's going to happen for the rest of his life, whether people mean to or not. I even had to recently call and get a new insurance card issued for one of my sons because they spelled it Guava instead of Gauva.
I'm always being called Ann or Anne when my given name is Annie. And of course I always introduce myself as Annie cause that's how I like to be called cause well, it's my name. The majority of people will call me Annie, but there have been a few that insisted upon calling me Ann. In high school I'd always sign my assignments and papers as Annie, and if someone called me Ann, I'd say "It's Annie" and then answer their question.