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