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