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