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