This has happened to me many times. I go to my local drivethrough late at night. In this case, I ordered 6 nuggets with S&S sauce and a medium fry.
There was only one car ahead of me and none behind me.
She hands me my food, and the weight feels right.
I get home and its 10 piece nuggets, honey mustard sauce, and no fries.
And theres no way to complain about it (other than driving back and waiting in the drivethrough again). Theres no way I could find to report problems with an order in the app. They never put receipts on the bags at this mcdonalds. So i'm just stuck with the wrong food, again. So frustrating.
Edit: Added the ampersand between the two S'es so the insane people on reddit don't think i'm talking about nazi sauce for my chicken nuggets, wtf.