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