TAMPA, Fla. — Publix and a health care firm that provides therapy for children with autism are locked in a multimillion-dollar legal battle over unpaid medical bills for children of Publix workers. Its lawsuit, filed in Broward County, states that Publix has refused to pay medical bills since October despite pre-authorizing therapy sessions through its self-funded health insurance plan. It provides autism therapy in 12 states and Puerto Rico. Meanwhile, Publix has continued to pre-authorize autism therapy with ABA Cares as recently as last month, Barker said. ABA Cares is a member of The Council of Autism Service Providers, a nonprofit trade organization that represents about 430 therapy providers.