How do i complain about mcdonalds being slow and unorganized ...

u tell them

Call their corporate office with specific details. I think first you have to understand the volume of orders they get vs the amount of staffing provided to fill them. They deliver through all major food delivery services (GrubHub, UberEats, Postmates and Door Dash) and in addition still have their always large in person and drive through amount of customers. Especially when it comes to this location which has been very busy for years and only seems to get busier because it's local area keeps growing.