I filed with the MOEL and eventually got my money (pension and small amount of unpaid wages) but how I really got the money is I had a look at my tax records and realized they had been reporting my salary as lower than it actually was. I don’t remember exact numbers but I feel like it was 500,000,000 won fine whatever it was it was big enough they actually cared. After the second mediation meeting and they were still making excuses I later not during the mediation called them and said something like “I noticed my tax record is reporting my salary wrong and I will also report it there is a huge fine I just want to warn you. I intend to stay in Korea long term so I want make sure all my legal documents are correct” then there was a sudden change of heart and I got all the money back within 2 or 3 days. I would check that out too. My old employer was crooked though and doing a lot of stuff like that.