hospital visit tourist Korea late night bus Korea night transportation Korea missed last subway Korea taxi at night Korea visa free korea Korea tax refund korea tourism guide Myeongdong tax kiosk tourist medical emergency Korea Tax refund in Korea korea sim card korea travel tips esim korea tourist exit record Korea k-eta korea VAT refund Korea korea connectivity 외국인 택스 리펀 immigration overstay decision Korea korea mobile internet 공항 환급 방법 tourist exit procedures Korea 서울 쇼핑 환급 overstay clearance Korea tourist overstay Korea consequences overstay exit risk Korea travel to korea korea entry requirements 한국 세금 환급