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