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