The department shall keep accurate books, records, and accounts of all of its dealings, and these books, records, and accounts are subject to an annual audit by an auditing firm selected by the department. The auditing firm or the department shall also conduct a selective audit of entities making payments to, or receiving payments from, the department to determine whether redemption payments and applicable processing fees are being paid to the department on all beverage containers sold in California, and that refund values and processing payments are being paid out properly by the department.