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