Beyond pissed..

My daughter is turning 5 tomorrow, me and her father have been separated since she was 3 months old. I’m 36 weeks pregnant with my current husband. My parents planned a birthday party for her tomorrow, mind you, I notified her father about this a week in advance. She is with me every year on her birthday. So, tonight when I texted him to confirm that I would be picking her up in the morning he responds with “I’m actually taking her to lunch, you can pick her up at 5pm” WTF. He basically told me to cancel her party that my parents planned for her during the day so he can take her to lunch. I asked him how he could do something so nasty to me, that my parents paid for everything already and he doesn’t care. My blood is boiling. I don’t even know what to do or why he’s pulling this shit when I always let him take her to his family plans and parties when he wants. I’m livid. What should I do?