Theft by waitress and horrible food

I ordered two meals and dessert; The first was Quater chicken and chips, the second one was 1/4 Chicken combo and chorizos. When I was placing my order, I had requested the 1/4 chicken of the 1/4 chicken combo to be hot and for it to be a leg. She told me that I cannot choose the part I want. She then asked me what cooldrink I would like, I responded by saying Fanta g****. When the order was ready, she called out the order number. I gave her the receipt; she checked it and packed it. when we were having our meals in the car because we ordered takeaways, we realised that the cooldrink was not packed and the chicken and chips tasted dry and old. I called the store to report the issue and was told that the next time I drive by, I can come in a collect my drink. I said to the Manager that I don't drive there often as I reside in Johannesburg and had only stopped there as I was coming from Lesotho. I also highlighted that I feel what the waitress did was deliberate, intentional and comes across as theft. She took the receipt, checked it and packed the meals. How does she not pack a cooldrink when she checked the slip? I would like my money back for the cooldrink as what happened should not have happened. The store was practically empty and there we only two meals ordered of which one of them being combo means there's a cooldrink, so how do you no pack a cool drink? I am not even going to start about how tasteless and dry our chicken was and the hot flavour was anything but hot. Please assist me in getting my money back. Thank you. I am extremely disappointed and if this kind of conduct continues, it will make sure that Mochachos loses many customers..