Overpayments and refunds.
(a) Any person believing that he has overpaid any tax due under the provisions of this chapter may file, in writing, a claim for refund with the Commissioner of Revenue Services within three years from 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 section constitutes a waiver of any demand against the state on account of such overpayment. Not later than ninety days 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 State Comptroller of the amount of such refund and the State Comptroller shall draw an order on the State Treasurer in the amount thereof for payment to the claimant. If the commissioner determines that such claim is not valid, either in whole or in part, he shall mail notice of the proposed disallowance in whole or in part of the claim to the claimant, 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 claimant. 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 claimant has filed a written protest with the commissioner as provided in subsection (b) of this section.
(b) On or before the sixtieth day after the mailing of the proposed disallowance, the claimant may file with the commissioner a written protest against the proposed disallowance in which the claimant sets forth the grounds on which the protest is based. If the protest is filed, the commissioner shall reconsider the proposed disallowance and, if the claimant has so requested, may grant or deny the claimant or the claimant's authorized representatives an oral hearing.
(c) The commissioner shall mail notice of his determination to the claimant, 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 claimant.
(d) The action of the commissioner on the claimant's protest shall be final upon the expiration of one month from the date on which he mails notice of his action to the claimant unless within such period the claimant seeks judicial review of the commissioner's determination pursuant to section 12-330m.