The Commissioner shall promptly pay all taxes, fees, dues, charges, and penalties and interest which he is authorized to collect under this title to the Office of Treasury and Fiscal Services to the credit of the general fund. The Commissioner, however, is authorized to make refunds of or to allow credits for any amounts which have been illegally or erroneously paid or collected pursuant to any provision of this title; and such payments to the Office of Treasury and Fiscal Services shall be less the amount of any such refunds or credits, provided that no refunds or credits shall be allowed under this Code section unless a written request for such refund or credit is filed with the Commissioner within seven years from the date of payment or collection of the amount for which a refund or credit is claimed.