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