I don't get what he did wrong? You're both being equally childish.
Let me explain it from his perspective, cos most guys are similar.
He had to be busy for the day, but wanted an excuse to spend the day with you. See how he asked you? He obviously didn't need the help, he just wanted your company. Then, as he get's irritated by the fact you're not really spending any time together, he's on a short fuse and then when he tries to force some contact, you don't help him so he snaps, and just unfortunately it managed to insult something you feel strongly about. Just chance. Then he tried to call you constantly and you ignored him, so he assumed you were upset and didn't want to talk. So obviously, that upset him. Then when he finally gets to see you, he puts his arm around you to try and comfort you and see if you too are still good. Then a bit of miscommunication, which from his point of view may have seemed like you were basically saying "no" after he said "friends?" Then he rang you because he didn't want you to go, and you further insisted you're leaving. This, of course, upset him even further. He's tried hard all day to spend some time with you and you're just not having it. Then he even tells you "it feels like a wasted weekend" then you show no emotion back, just give him a plain and frankly rude reply. He then, even more annoyed, just starts acting childish.
All he was trying to do was spend time with you, but of course from your point of view you think he's a childish bully. You have to learn to look at it from his point of view
He thinks you don't wanna spend time with him.