Manners on the phone (vent)

People seriosuly need to learn some. I'm on the phone all day and I HATE when people call me from the bathroom! why would you do that? I do it if I'm talking to my mom only but is my mother!! not to make a dentist appointment!!!!
But somebody JUST called me and BURPED SO LOUD AND LONG, unbelivable! how can you do that?? and the woman was at work!!!! When I was about to say something (because i was, that was very disrespecful and disgusting) my boss walked in talk about bad timing!!!