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