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