In no event shall any mistake made by the License Collector in stating the amount of the tax or receiving such tax prevent or prejudice the collection by the city of the amount of tax actually due, together with any penalty applicable thereto, and all costs of collection, from any person for conducting any business activity without a license or for refusing to pay the taxes specified in this chapter. Overpayments, erroneous or duplicate payments shall be reimbursed upon approval of the City Council.
(`83 Code, § 5.04.090)