As a person who is good friends with the receptionist at Wharton, I can tell you this happens a lot. Unfortunately, as with most receptionists, they don't have the power to change their IT system, or to give you an immediate answer. However most people require this of them. They try to be polite as long as they can, but sometimes people have a bad day and let it go.
She probably shouldn't have said that to you, but that being said it's probably not right for you to write such an email either. I would have tried to contact others in the school, explaining my situation, and then giving them a week or so- not a day- to resolve things.
But since you don't want to go to UVA anymore, that's probably not a problem.