I have a court ordered custody agreement that states my son is with his father on Saturdays for 10 hours. He verbally canceled several weekends that I wrote down and up until now he has not shown up to the canceled dates. One of the dates that he has canceled was in June, the weekend after my sons birthday. I decided to plan my sons birthday party on that day (the venue is paid for, invites already sent out) as soon as his dad found out about it he wanted the day back saying I have no proof he canceled. There is also a clause in our order saying that days will be switched for family events (trading a Saturday for a sunday). He is refusing any other day and said that if I do not give him our son on that day he will report the "proper authorities." Is there anything I can do?