It will be worth checking to see how long the court order is valid for. I had exactly the same. Cost me a fortune as she wanted to go to court. I then found out that the court order was only valid for 1 year. As some as that time was up I went to the CSA aymed with all the info. They weren't aware that the court order was only valid for a certain amount of time.
I know this sounds a little mercinary but I was having my boys all the time...