In order to defray a part of the expense necessary to provide the surveillance, supervision and inspection of persons as required under the terms of this chapter, there is hereby fixed a license fee or police tax, which shall be collected from any person engaged in the private detective business or conducting a private detective agency of $50 per annum. If any application is granted during the calendar year, the fee shall be paid pro rata for the balance of the current year. In no event shall there be any refunds of license fees or police taxes paid under this chapter. The fee shall be paid to the assessor and collector of taxes who shall issue a receipt therefor on a form prepared by him for that purpose. (Ord. Nos. 4039; 4996)