I grew up in Philadelphia, where "D'ya wanna"" is slang for, "Will you please?" My dad said when we first moved there and his secretary would say, "D'ya wanna call (Such-and-such Other Lawyer) back?" he'd think, "No, I don't wanna!" He picked up on it pretty quickly though, and to this day my family says "D'ya wanna?" for "Will you please?" (This is possibly the only part of my way of communicating my husband has ever picked up; he says "D'ya wanna" too.) This means I generally hear something like, "Do you want to go pick up the pizza with me?" as a polite request, rather than someone actually asking if it's something I want to do. (This caused some confusion with Rock Band, as I thought people were saying, "Will you please play bass/sing?" as opposed to knowing if I wanted a chance to do those things.) I very rarely refuse a polite request, unless I actually physically cannot do it. I will do it even if it's very hard or inconvenient, which means that when I say, "No," people know I have a good reason.
I can't honestly remember the last time someone wouldn't take no for an answer, aside from my husband in his sleep. He sleep talks and is often completely irrational, such as insisting we are in the car and I have stopped in the middle of an intersection. He won't take, "No" for an answer when I say, "No, I can't step on the gas, we're in bed...." Last time that happened, he shouted, "I know where we f*cking are!" hopped out of bed, and stormed out slamming the door, only to return less than a minute later to say, "I'm sorry, you're right...we were in bed."