The receiver of taxes for the city of Philadelphia be and he is hereby authorized and directed to refund all state and city taxes that may have been paid to and collected by him on duplicate and erroneous assessments, to the person or persons who may have so erroneously paid the same; all amounts to be refunded out of the taxes collected in the respective wards, and in the respective years in which said errors occurred: Provided however, That proper vouchers of allowance of such errors by the city commissioners of said city shall be first furnished to the said receiver of taxes: And provided further, That the lien of the taxes on the real estate wrongfully paid shall not have been discharged by a judicial sale, or otherwise.
53 P.S. § 17055