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