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