Although I have never had to deal with this particular issue, so far anyway, I do make sure to tell all of my client families that I will use a local collection agency to recoup unpaid fees upon such an event. By using a collection agency, you will not get the whole amount owed, because they have thier fee (this agency that I spoke with it's 30%) but some is better than none AND it sends the message that you are serious.

HTH,