An insurance company calling itself the California Assn. of Concerned Senior Citizens has been ordered to stop soliciting senior citizens to buy supplemental Medicare and life insurance policies, state officials said. A state Department of Insurance investigation revealed that insurance agents formed the company two years ago and allegedly misrepresented its policies as group benefits when it was actually selling individual policies. Complaints against the company also alleged that its agents misrepresented the requirements, benefits and availability of its policies. Without admitting any wrongdoing, the association, its parent company, California Assurance Corp., and five licensed insurance agents agreed to stop the allegedly deceptive practices.