Section 8. Public dissemination of any promotional material, evidence of coverage, health maintenance contract or any other statement with respect to a health maintenance organization, which is untrue, deceptive or misleading, shall constitute an unfair and deceptive practice under the provisions of section two of chapter ninety-three A. Every health maintenance organization shall keep on file, available for inspection by the division of insurance, copies of all educational materials, displays, evidences of coverage and all materials of any promotional nature released for public dissemination. The commissioner may forbid the use of any such material if he finds that it is either untrue, deceptive, or misleading.