The department shall, pursuant to the provisions of Article XXVII,¹ refund all taxes, interest and penalties paid to the Commonwealth under the provisions of this article and to which the Commonwealth is not rightfully entitled. Such refunds shall be made to the person, his heirs, successors, assigns or other personal representatives, who actually paid the tax: Provided, That no refund shall be made under this section with respect to any payment made by reason of an assessment with respect to which a taxpayer has filed a petition for reassessment pursuant to section 2702 of Article XXVII² to the extent that said petition has been determined adversely to the taxpayer by a decision which is no longer subject to further review or appeal: Provided further, That nothing contained herein shall be deemed to prohibit a taxpayer who has filed a timely petition for reassessment from amending it to a petition for refund where the petitioner has paid the tax assessed.