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