Unemployment Benefits approved, now employer appealing claiming misconduct and severe misconduct.

Hello & help please. I worked at a bank for a year and I unfortunately had a difference on day of 1,000.00 shortage. I knew at the end of day racking my brain how this could happen, which customer this difference came from. My coworker who was helping locate my difference called the customer on my behalf since she had known him when she originally opened the act. He denied any diff. He came in nex day asking me about my diff saying wow that was a lot of money if you did not find it. We never told him the amount. This already now confined it for me. So after 3 wks of my being investigated, security tapes reviewed. They fired me, I was told they had to be consistent with others in the same situation. I was extremely upset. I got a termination letter stator I was being let go becaus of policy violation for faliure to meet performance standards. I have this letter proving such and an email to hr with a timeline of how things were going on through out the investigation.