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