Lots of threads on pet peeves and poor manners and such, but, what REALLY, REALLY pisses you off?

Today, I was talking with contractors for a simple job. One lad was on the phone with me asking far tooooo many questions which can only be answered when he sees the "job" trying to impress/snow me with his expertise and credentials, over and over.

That's annoying enough but he did the one thing I cannot abide... he asked me questions and then did not allow me to answer before asking more questions or giving me "options" in defining his question(s).

If you ask me a question, I will... pardon me? Okay, let me answer your first question... what?... no, that doesn't matter in this case... I asked you... what?... AARRRRRRRRGGHHHHHH! He interrupted me repeatedly. I wanted to reach through the wire and choke the bastard!

At one point, I stopped talking altogether. Silence. He asked if I was still on the phone. I asked, "Do you want to come look at the job and quote on it or not? Yes or no. If you do, tell me when. Otherwise this conversation is over because you are not listening to me."

Where has the common respect of proper conversation gone? Are people just brain dead or uneductaed? Isn't it just good manners to allow someone to answer a question?