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