Is it so hard to get an order right.

I am sad to say my last 5 visits to this mcdonalds have all been disappointing. After the first disappointment i made an effort each time to confirm my order and ensure that i was being understood. Not one of these times did i get what i ordered. Furthermore two out of the five times i got someone elses order instead of my own. How does this even happen? I find it hard to believe that it is so difficult to just give me what i ordered without me having to open each box in my order to ensure that i infact got what i asked for. I am a frequent customer yet lately i dont even want to go as i am pretty sure i will be disappointed.