Except as provided in §§ 3.2-1721, 3.2-1812, and 3.2-2408, the Tax Commissioner shall immediately notify any person who fails to pay an assessment pursuant to Part B of this subtitle and shall add a five percent penalty to the amount due. If such deficiency is not paid within 30 days after the date of such notice, then the amount of the deficiency shall bear interest, in accordance with § 58.1-15, from the date the amount was due, and the Tax Commissioner shall collect any interest as part of the delinquent amount. If any person is delinquent in any payment of the money due or interest thereon, then the amount shall be collected by civil action in the name of the Commonwealth at the direction of the Tax Commissioner, and any person adjudged to be in default shall pay the cost of such action. The Attorney General, at the request of the Tax Commissioner, shall institute action in an appropriate court for the collection of any money due under Part B of this subtitle, including interest thereon. The Tax Commissioner may waive or remit such penalty, or portion thereof, in his discretion for good cause shown.