If it appears that as a result of a mistake an overpayment of a tax, penalty, or interest was made which was not due under the provisions of this chapter, then such amount must be     credited against any amount due under the provisions of this chapter from the person who made the erroneous payment or must be refunded to such person; provided, that the person entitled to the overpayment makes a written claim for it to the state tax commissioner within six years after the date the overpayment was received by the commissioner. If a refund is authorized by the tax commissioner, the tax commissioner shall certify the amount of the refund, the reason for it, and the name of the person entitled to it to the office of management and budget which shall thereupon draw a warrant for such amount on the funds to which the overpayment was credited.