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