they are playing word games with you .. you have to dispel the myth you were driving ..you were not driving(working for profit)
https://www.law.cornell.edu/definitions/index.php?width=840&height=800&iframe=true&def_id=fbca62c15d0f78463868dcfd63260780&term_occur=999&term_src=Title:49:Subtitle:B:Chapter:III:Subchapter:B:Part:390:Subpart:A:390.5T
Motor vehicle
Motor vehicle means any vehicle, machine, tractor, trailer, or semitrailer propelled or drawn by mechanical power and used upon the highways in the transportation of passengers or property, or any combination thereof determined by the Federal Motor Carrier Safety Administration, but does not include any vehicle, locomotive, or car operated exclusively on a rail or rails, or a trolley bus operated by electric power derived from a fixed overhead wire, furnishing local passenger transportation similar to street-railway service.
*passengers*
Charter transportation of passengers means transportation, using a bus, of a group of persons who pursuant to a common purpose, under a single *contract*, at a fixed charge for the motor vehicle, have acquired the exclusive use of the motor vehicle to travel together under an itinerary either specified in advance or modified after having left the place of origin.
https://www.law.cornell.edu/cfr/text/49/390.5T