The California Federation of Teachers and other employee unions have filed a complaint with the U.S. Department of Education over the actions of a regional accreditor, the Accrediting Commission for Community and Junior Colleges. The unions had previously lodged their concerns directly with the commission, which accredits California's two-year colleges and is an arm of the Western Association of Schools and Colleges. They alleged that the accreditor had acted improperly in slapping a severe sanction on City College of San Francisco -- which faces possible closure -- as well as in its oversight of other community colleges. The commission last week rejected those claims, saying it has followed procedures. So the unions this week asked the Education Department to force the commission to respond more fully to the complaint.