The car was returned around noon but the office was still not open, at the time when most people would return the car. Due to closed Hertz office at Kiruna Airport, no joint inspection or discussion occurred. A week later we got a bill for cleaning with OZONE!?, since the office claimed the car smelled of smoke. The charge was applied without any prior communication. None of us are smokers! I asked them to explain, where they found the smoke smell - no reply.