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