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