Child care / custody disagreement, advice needed!

[Icantremembermyusername]

Is there anything in can do about this situation or do I just need to put it behind me each time and carry on?
Ex and I split when DC was little so our access arrangements have changed as DC has gotten older and we are now agreed on one evening per week and EOW. No court involvement.
Ex has DC (tween) one evening a week (3.30 - 7.30) and EOW. Ex says he cannot commit to a certain evening each week so each weekend we agree on an evening which suits DC and us. At least once a month Ex gets in touch on the day to say he cannot spend time with DC after all. This happened again yesterday. DC was upset but resigned (getting used to it now). I was pissed off because he let DC down and yes, I will admit it, I was pissed off because I had to reorganise my evening "off".
He can't do today as he is 'busy' and I'm half expecting him to ask for this weekend's contact time to be reduced...(this has been a pattern for a while).
I have tried to explain to him the effect of his behaviour on DC (increasingly not wanting to spend time with their Dad, poor self esteem as he just drops them at the last minute, etc), and he just doesn't seem to care! Or least, not enough to commit to the arrangements he makes.
There is no good reason why he "can't" do the evenings he chooses, he just opts out.
Is there anything I can do to "make" him stick to his arrangements?
Thanks for reading - any advice most welcome!

In my experience , a court order is on the resident parent and not the parent who has the child EOW for example. So no, nothing you can do

Court involvement

You've tried to explain to him the effects on DC and it hasn't done anything to change the situation. This is no longer an amicable arrangement

@daemonologie would a court order work with a tween who is increasingly not visibly fussed about spending time with him even though his lack of contact is making them miserable?

If he doesn’t make his tween a priority, in 2-3 years his teen won’t make him a priority. Has he thought of that do you think?

@LittleLegoWoman yes, I have explained this to him and he agreed and then was 'busy' the next week.

You can’t force him to see his son through the courts unfortunately.

If dad is reasonably reliable about the weekend, even if he reduces time, then I would consider changing to just EOW and cancel the midweek night.

i think it might be better for your sons self esteem to see his dad less, but not get cancelled on.

Unfortunately you can’t make him parents. It’s ridiculous though. Imagine if you were just too busy to look after your child - it just wouldn’t happen.