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