Followed manager's advice on short drawer and got fired?

I was working the late shift at my last job, and discovered when closing out my drawer that it was about $35 short. Because I worked at Wendy's and they automatically fire you if you are more than $20 off, I panicked and asked the GM what I should do. He told me to do a void/refund for the amount i was off, and bring it right. I did so, but 5 days later I was called in and told I was being let go for being short, and also accused me of altering company documents and fraud. I stated that I didn't steal ANYTHING, and that I simply did what the GM told me to do. They also said that the slip tha we are supposed to put under the register when we do a void/refund was missing...I put that slip there like I always do. Anyway, I filed for UI and was eventually approved, however, the employer appealed it...do they have a case? During my eligibility review, I told them exactly what happened, my former employer sent them all the paperwork including the policy and I won. They have sent in no new information other than a letter saying that they called me in the day AFTER it happened, which isn't true...it was nearly a week later. How do my chances stand?