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