My Mom Is Being Told To Pay Back $13k Of Unemployment After Previous Employer Changed Reason For Termination

My mom received unemployment from May 2023 until late 2023. She had no issues receiving it each week.

Then in May 2024 she got a letter saying she owed MORE than what she was given because the employer is saying she was fired for a reason that I assume falls under misconduct - although arguable the reason is hardly misconduct. Anyways, has anything similar happened to someone else? The total amount is $13k and that's a big chunk of change to simply pay back. It should have never been approved or it should have been caught a YEAR ago.

Edit: after reviewing the letters, it appears that they are saying she said the reason for unemployment is due to lack of work, and that the actual reason is termination. The thing is she never filled out the forms, someone from the unemployment office did it for her. So I am thinking they knew she didn’t qualify for the UI due to misconduct so they put “lack of work”. The unemployment office employee knew very well why my mom was fired and what was going on.