Unfair dismissal

I was an employee and got dismissed on an offense I believe I and know I did not do. They said I was short of an amount of R549 for card payments. This incidence took place on the 9th of August 2024 but I was only informed on the 26th of August which bothers me because for every end of the shift, you get cashed up by your manager and they count if your sales correspond with the amount of money you have before you can go home. And upon my cashup the manager did not pick up any irregularities and even on the day after up until the 26th. So after that they gave me a warning and had a trial/hearing where they found me guilty of the situation, but what confuses me is that during cashup tge manager can't close of the banking if it doesn't balance so how did my manager do that, and why did it take so many days to pick up the fault, and why did they deny me footage to trace and see what exactly could've happened during the time these orders they claim were not cashed took place. And if I was found guilty then why is the manager not guilty for not perfoming their duties with due diligence. This is unfair and I need answers!