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