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