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