(a) Any taxpayer subject to any tax or fee under § 12-263q or 12-263r, believing that it has overpaid any tax or fee due under said sections, may file a claim for refund, in writing, with the commissioner not later than three years after the due date for which such overpayment was made, stating the specific grounds upon which the claim is founded. Failure to file a claim within the time prescribed in this subsection shall constitute a waiver of any demand against the state on account of overpayment. Within a reasonable time, as determined by the commissioner, following receipt of such claim for refund, the commissioner shall determine whether such claim is valid and, if so determined, the commissioner shall notify the Comptroller of the amount of such refund and the Comptroller shall draw an order on the Treasurer in the amount thereof for payment to the taxpayer. If the commissioner determines that such claim is not valid, either in whole or in part, the commissioner shall mail notice of the proposed disallowance in whole or in part of the claim to the taxpayer, which notice shall set forth briefly the commissioner’s findings of fact and the basis of disallowance in each case decided in whole or in part adversely to the taxpayer. Sixty days after the date on which it is mailed, a notice of proposed disallowance shall constitute a final disallowance except only for such amounts as to which the taxpayer has filed, as provided in subsection (b) of this section, a written protest with the commissioner.

(b) On or before the sixtieth day after the mailing of the proposed disallowance, the taxpayer may file with the commissioner a written protest against the proposed disallowance in which the taxpayer sets forth the grounds on which the protest is based. If a protest is filed, the commissioner shall reconsider the proposed disallowance and, if the taxpayer has so requested, may grant or deny the taxpayer or its authorized representatives a hearing.

(c) The commissioner shall mail notice of the commissioner’s determination to the taxpayer, which notice shall set forth briefly the commissioner’s findings of fact and the basis of decision in each case decided in whole or in part adversely to the taxpayer.

(d) The action of the commissioner on the taxpayer’s protest shall be final upon the expiration of one month from the date on which the commissioner mails notice of the commissioner’s determination to the taxpayer, unless within such period the taxpayer seeks judicial review of the commissioner’s determination.