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