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