Ha! I'm sorry, I guess the more I read here... the more I want to laugh at people who are this crazy and self-centered, and expect to huff and puff like the big bad wolf and have everyone drop everything to suit their moods.

First, let me say - if this was somebody that I had a good relationship with, who had already showed a lot of caring and patience towards me, I would honestly consider how they were feeling and whether this was something that I could give in on, to help them feel better.

But in this case, where the relationship is already sour, and where you've already explained to him why you can't see him on his birthday, he's just being a big, whiny, brat. I think I'd have a tendency to say something that sounds vaguely empathic, then drop it and hang up. Sort of like you might do with a child having a tantrum? Like, "Yeah, it really sucks that I can't get out there today. I'm glad I'll be able to see you tomorrow then! Gotta run, see you later!"

But then... I'd say put it out of your mind. Not the trip the next day, I don't mean to blow him off... I just mean... don't let his words stay in your head and cause you additional stress/worry/grief. Just let them float away like a bubble, because it's all his "stuff", not anything you're doing... so no use holding on to it... if that makes sense.

Anyway - sorry your dad's being bratty