Poor service and incompetency

I was at McDonald's Riversands Fourways, and I put through an order at the drive through for 4 Boere burgers, 1 Spicy fold over and 1 Oreo Mcflurry. So I paid and on my way to collect and on my way to collect I decided to check the slip because the total amount seemed low and I realized she ordered only 1 Boere instead of 4, so I collected the incomplete order and went back to order only to realize that my Mcflurry is below the normal size when I asked them to correct it they decided to give me a watery Mcflurry then when I go back to the manager to request a proper Mcflurry she told me it's wet and I decided to ask for my money back, they wasted my time and provided horrible service speaking in a language I don't understand.