(a) It shall be unlawful for any city official, employee, or other officer to pay or cause to be paid any salary or compensation to any person in the classified service of the city, for personal services, unless the payroll estimate, voucher, or account, for such compensation, containing the name of the persons to be paid, shall bear the certification of such persons’ department head or appointing authority that the person or persons named therein are employees of the city and are legally entitled to receive the sums stated therein and such payroll or voucher must be approved by the director.

(b) Any sum paid in violation of this part or the rules and regulations adopted thereunder may be recovered, in any action maintained in the name of the city, by the city attorney, or by any citizen or taxpayer of the city, from the officer who made, authorized, or approved such payment or who signed or countersigned any voucher, payroll, check, or warrant for such payment, or from the sureties on the official bond of such officer. All money recovered in such action shall be paid into the city treasury.

(c) Any person appointed or employed in violation of this part, the rules and regulations adopted, or the orders of the board, who performs service for which he or she cannot be lawfully paid out of the municipal funds, may maintain an action against the appointing authority to recover the agreed pay for such services, or the reasonable value thereof, and no officer shall be reimbursed by the city at any time for any such sum recovered and paid.

(d) If the director wrongfully withholds certification of the payroll, voucher, or account of any employee, such employee may maintain a proceeding to compel the director to certify such payroll, voucher, or account.

(e) A 30-day month shall be used for the purpose of calculating the pay of employees compensated on a monthly basis.