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