Ken,
I am sorry you had to go through this experience.
If indeed the company that responded to your request for service was a bonafide, legite contractor, with a state license, then you are protected if he/she did any work not per code.
Contact the state licensing board to find out proper procedure to make a claim. Plumbing Contractors are required to have a performance bond of $7500. This is there for you to make a claim against.
My hope is that all his/her paperwork is in order. This is just another reason not to be afraid to ask for Licensing information and Liability insurance before a contractor sets foot on your property. Do not only ask, but take the time to verify. Good Luck.
Bill
The Local Plumber
Tustin, California
http://www.TheLocalPlumber.com