Saramin visa sponsorship Korea work visa korea unpaid salary Korea foreigner teaching jobs Korea company closed Korea visa job termination Korea foreigner Seoul Global Center English jobs Korea foreign worker ghosted Korea non-teaching jobs Korea change job korea visa part-time jobs Korea resigning job korea freelance jobs Korea jobs in Korea for foreigners JobKorea employer shutdown foreign worker Korea fired in Korea visa foreign worker resignation korea employment visa quitting job Korea foreigner expat career Korea Kowork employer no response Korea LinkedIn Korea XpatJobs work visa status Korea job search guide work visa korea rules KOTRA job fair foreign worker job change foreigner jobs Seoul work in South Korea 2025 Korea job platforms notice period korea