Poor Customer Service

I went to Zambezi Junction,there's a complex there and you find Steers. I decided to buy the following, a Wacky Wednesday, extra fries as well as a 1/4 Chicken with Chips. I paid and waited from 17:38 to 18:12 for a order which wasn't well prepared. My order number is 5426 and all along they have been calling orders and not mine. When I follow up and ask, where is my order? Since you calling order 5427 and all along to order number 5435. It isn't logical that people arrive after me and I have waited in a line, paid for the order but yet we sitting on order number 5435. Where is order number 5426, and the response I get is "it is on the way, it is chicken. It takes long." But all the people called up are ordering three or more burgers and still have milkshakes and I did see another chicken being served. It can not be the case and when I get home, I don't receive value for money. I asked for the chicken to have extra sauce but it didn't. It is dry and the burgers are also dry. They not juicy as I know them to be and this for me doesn't make sense. If I am waiting and wait for such a long time, can I not be disappointed that even the order that I am paying for is not prepared as I asked. The service is slow and not encouraging at all, I was not the only one seeking clarity about what is going on with my order. It is even more insulting to arrive and see Mr D Food drivers arriving and receiving more attention. A lady also arrived at the shop asking for clarity on her order and the line. Yes it can be busy and yes it is a lot of orders coming in. But no way can I wait for a order from 17:38 to 18:12 and receive poor service. I refuse to believe and accept the logic is because I ordered a 1/4 Chicken and that extends the waiting period and a dry chicken to top it off. I'm standing outside waiting and hearing order numbers being called and these people are ordering more food than me and when I questioned the logic. That is the excuse and answer given to me as a customer. Please honestly it doesn't make sense to me. How did we get to order 5435 without serving order 5426 going out. The orders before me are not ice creams only. If it was I would understand but no, it is big orders. Two or three paper bags with more than just burgers inside. I payed attention because I was concerned about the length I waited and kept going inside and not receiving feedback.