"SECTION 229. Recovery of Tax Erroneously or Illegally Collected. - No suit or proceeding shall be maintained in any court for the recovery of any national internal revenue tax hereafter alleged to have been erroneously or illegally assessed or collected, or of any penalty claimed to have been collected without authority, or of any sum alleged to have been excessively or in any manner wrongfully collected, until a claim for refund or credit has been duly filed with the Commissioner; but such suit or proceeding may be maintained, whether or not such tax, penalty, or sum has been paid under protest or duress.

"In any case, no such suit or proceeding shall be filed after the expiration of two (2) years from the date of payment of the tax or penalty regardless of any supervening cause that may arise after payment: Provided, however, That the Commissioner may, even without a written claim therefor, refund or credit any tax, where on the face of the return upon which payment was made, such payment appears clearly to have been erroneously paid.

"SECTION 230. Forfeiture of Cash Refund and of Tax Credit. -

"(A) Forfeiture of Refund. - A refund check or warrant issued in accordance with the pertinent provisions of this Code, which shall remain unclaimed or uncashed within five (5) years from the date the said warrant or check was mailed or delivered, shall be forfeited in favor of the Government and the amount thereof shall revert to the general fund.

"(B) Forfeiture of Tax Credit. - A tax credit certificate issued in accordance with the pertinent provisions of this Code, which shall remain unutilized after five (5) years from the date of issue, shall, unless revalidated, be considered invalid, and shall not be allowed as payment for internal revenue tax liabilities of the taxpayer, and the amount covered by the certificate shall revert to the general fund.

"(C) Transitory Provision. - For purposes of the preceding Subsection, a tax credit certificate issued by the Commissioner or his duly authorized representative prior to January 1, 1998, which remains unutilized or has a creditable balance as of said date, shall be presented for revalidation with the Commissioner or his duly authorized representative or on before June 30, 1998.