"A civilization is any complex society characterized by the development of a political state, social stratification, urbanization, and symbolic systems of communication beyond natural spoken language (namely, a writing system)."
Even in most post-apocalypse antiutopia science fiction, all of these attributes are present except perhaps urbanization. E.g. a roving gang with a warlord at its helm has a political state and social stratification, and they would still have access to pencils.