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