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