Please teach Tanya Mcdonalds Daveyton some manners

I had a an expensive terrible and horrible experience at McDonald's Daveyton drive through. I ordered a Boerie hash burger with an extra boerie patty. Tanya the cashier charged me for an extra hash brown which is more expensive than a patty and still didn't add it on my order. I had to drive back and petrol is expensive nowadays. They maged to fix my issue but Tanya didn't even appologies. What about my petrol. This could have been easily avoided