My question involves independent contractors in the state of: Arizona; I am a Gov't contractor designated to conduct examinations on individuals seeking the license to operate an aircraft. My business is primarily referral driven. A local attorney contacted me for my services and a date was set to conduct the evaluation. An evalution can take up to 5 hours and my fee is $400 regardless of the outcome. I am required to advise the applicant of the three outcome possibilities before I begin the evaluation. One outcome possibility is the issuance of a disapproval. A disapproval is issued whenever the applicant does not meet the published standards set forth by the FAA. Those standards are in writing and fully available in advance for the applicant as part of their training literature. I then accept cash or personal check and begin the process. This applicant received a disapproval during the ground/oral portion of the evaluation. About 4 hours later I received a phone call from this applicant/attorney attempting to renegotiate the terms of the contract citing he did not receive the services he agreed to. Specifically he wanted a pro-rated amount of my fee since the disapproval was issued fairly early into the evaluation. The following day, he put a stop payment on the check. I have filed a Small Claim (Summons and Complaint) and I would like to know what Arizona Revised Stututes can I cite to be best prepared to when I go to court.