Every towing firm, employee or agent in the process of towing, removing or impounding a vehicle as directed by an authorized officer, except vehicles to be towed as part of an investigation or suspected stolen, shall upon request of the owner or his authorized agent, release the vehicle at the scene. If the vehicle is attached to the tow truck, or otherwise "in tow," the regular, scheduled tow fee may be charged. When the vehicle is not yet "in tow" at the time of request, the release must be made, and no charge may be assessed except a customary and reasonable charge for mileage one way from the towing firm’s place of storage to the scene plus the usual fee for the tow truck operator. If the authorized fee is not tendered by the owner or his agent, the towing operator may complete the impoundment, towing or removal, as authorized.