The tax imposed under the provisions of this article and unpaid on the date when due shall bear interest at a rate determined in accordance with § 58.1-1812, from and after the due date until paid. If any person defaults in any payment of the tax or interest thereon, the amount shall be collected by a civil action in the name of the Commonwealth at the relation of the Board and the person adjudged in default shall pay the costs of the proceeding. The Attorney General, at the request of the Commissioner, shall institute an appropriate action for the collection of the amount of any tax past due under this article, including interest thereon.