Refusing Being Disrespected
It's your responsibility not to let anyone disrespect you, or speak to you in a way that doesn't show that they have any regard for you. You need to act and swiftly, and let them know that you value yourself and won't accept such a behavior from them.
It's unfortunate that many people don't speak up for themselves enough. They keep on swallowing such intolerable behaviors from people towards them. The truth is that, if you respect yourself - then you won't let anybody to disrespect you.
On the flip side, if you don't value yourself or think of yourself worthy of respect; that's when you take insults from people, without fighting back. Don't get it twisted, no matter how much you respect yourself; you may meet people who are just rude and absolutely arrogant.
These people will not care about your worth or who you think you are, they're usually very narcissistic people; and assume that they can speak to anybody anyhow. But you need to put them in their place, and let them know that they can do that with others, but not with you.
The reason why you have to stand up for yourself if someone is disrespecting you, is because; other people are watching. And when people see that you take such disrespect, they too will want to disrespect you - because they'll feel that you don't value yourself. Don't let them.