Please give me advice 😫

This is my situation I have a court order of my ex getting our son every other weekend but he is always canceling to pick him up on his days at last minute or tells me one thing and does the opposite I made reservations to get away this weekend which is when he has our son and like always canceled to pick him up at last minute and its pissing me off he hasn’t helped with anything over a year with his sons needs ignores my calls/texts when I contact him to pay his half of daycare but wont give me full custody he told me he doesnt want to be responsible for any of our sons finances,

this is driving me nutss.!! 😤😤🤬