Went to a property and found it to be between a gas station, super market, and other business. It was ordered as a single family residential appraisal. The assignment was too complex for me to complete. AMC says they don't have to pay me anything unless I complete the assignment (per USPAP) and I want them to pay for the trip fee (which entailed the trip, appraisal inspection, and preliminary data pull). I indicated that per USPAP that if at anytime during the appraisal process I find that I am not competent enough to complete the assignment that I am required to decline it. Is not indicating that they will not pay anything unless the assignment is completed a violation of HVCC?