Looking for opinions.

I get my kids two weeks per summer. In March my ex. agreed to extend one of my weeks by 4 days along with me agreeing to give her memorial day and labor day. (this was all agreed to in e-mail) She has now changed her mind and decided to stick to the court order. I had planned to visit with Family out of state which I do every year. The problem is that my relatives already paid for plane tickets and they are non-refundable. My kids were looking forward to this trip.

THe last time something like this happened my ex. decided that the kids soccer equipment she buys them is not going to come to my house. I finally explained to her that if she did not send it she could explain to them why they were not going to play soccer on my time. she relented and sent the shoes etc.. My children did find out about this through her and I know they just didn't want to have to hear about it.

What should I do about the fact that they are not going to go on vacation?