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