Family Dollar complaint: It’s not fair

I had got terminated because they said that $203 was missing out my drawer. I told them what had happened and they gave me a day to work and made me come in the next day to work 12 hours and told me that I was terminated without any, knowing first they were going to fire me instead, I told her what I did and what my manager that was working there did his name was Sam and a man came in to load his car just to tell you they never teach me how to load a card but they made me do it anyway without asking me first if I knew how to do it and I was doing good so far until this guy loaded his card and came back in and said his money did not load on his card, so I called my manager Sam and ask him what I should do so he came up stood next to me didn’t say anything the guys looking at me so I don’t know what happened after that but he didn’t say anything about me loading the cardigan and he didn’t say anything about that. The money was get it going to get loaded to his card after a few more minutes or he didn’t say anything about telling the guy about filing a complaint to the merchant that loads the card right thing by loading up his card and that’s how my drawer came up short but they still terminated me I don’t see how this is fair. I’ve been there for three months and they wasted my time.