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