personality formation

Maury is a young clinical psychologist who is new to private practice, and is working on a fee-for-service basis, meaning he doesn’t take insurance.
One of the clients he has been treating is a 20-year old man who was referred by his parents whom Maury had seen previously to consult on parenting for their younger child. This patient still depends on his parents financially, and they were writing the checks the client would bring to pay for therapy.
After a few months in which good progress seemed to be made, the client suddenly grew dissatisfied and began devaluing Maury and the treatment; he unexpectedly quit therapy, still owing an unpaid balance of over $600.
Maury had a good relationship with the client’s parents, and he is confident they would be happy to pay the balance. However, the client is an adult, and Maury does not have a signed Release of Information stating he can speak with the client’s parents.
Discuss what Maury can do to recover the unpaid balance. What ethical issues and concerns should he keep in mind? How might he avoid such a situation in the future?