When an insurance carrier has certified a motor vehicle liability policy under N.C. Gen. Stat. § 20-279.19 or a policy under N.C. Gen. Stat. § 20-279.20, the insurance so certified shall not be canceled or terminated until at least 20 days after a notice of cancellation or termination of the insurance so certified shall be filed in the office of the Commissioner, except that such a policy subsequently procured and certified shall, on the effective date of its certification, terminate the insurance previously certified with respect to any motor vehicle designated in both certificates. (1953, c. 1300, s. 22.)