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