McDonald’s complaint: Takeout order breakfast missing items

Dated 2832020 early morning 8am plus, I ordered takeout at Beauty World MacDonald outlet. My self kiosk order no is 2671, amount is $41.90. I noticed staff (female Indian manager) only packed 4 hashbrowns for my order. So I asked her to check before she sealed the paper bag. She ignored my question before passing over the package to her female colleague in yellow polo shirt. I took my package aside to check and told the staff that there is only 4 hash browns when I have ordered 3 Big Breakfast set, 1 family bundle C (comes with wrap Big breakfast set), chicken muffin with corn meal and sausage muffin set. I should have 5 hashbrowns in total. So I asked the staff in yellow shirt to top up the missing hashbrown. Once I reached home, I realized the chicken muffin is missing. So I called the outlet to speak to the female Indian manager to inform about the missing item. She said she will get her delivery man to deliver later. Until now, we never recieved the promised chicken muffin. We are really disappointed with the customer service provided by the outlet manager and the efficiency of the staff who did the packing. Where is the standard checklist? The staff should double check before passing the sealed package to customer. Thanks.