The Commissioner of Revenue Services may disallow any credit otherwise allowable for a taxable year against the tax imposed under this chapter if the company claiming the credit has any amount of taxes due and unpaid to the state including interest, penalties, fees and other charges related thereto for which a period in excess of thirty days has elapsed following the date on which such taxes were due and which are not the subject of a timely filed administrative appeal to the commissioner or of a timely filed appeal pending before any court of competent jurisdiction. Before any such disallowance, the commissioner shall send written notice to the company, stating that it may pay the amount of such delinquent tax or enter into an agreement with the commissioner for the payment thereof, by the date set forth in said notice, provided, such date shall not be less than thirty days after the date of such notice. Failure on the part of the company to pay the amount of the delinquent tax or enter into an agreement to pay the amount thereof by said date shall result in a disallowance of the credit being claimed.