I am beginning to think this varies considerably. I live some distance away from my Mother. I do an on-line shop for her once a month thru Tesco, obviously delivered to her house, and have been doing so for some years now.
The order is correctly delivered, at the right time, and the delivery people are very helpful. She is 86, and frail. They give her the frozen stuff separately, so she can put it straight in the freezer, and she says they are very pleasant. You can choose "no substitutions". This saves getting unwanted items.
Could this difference be anything to do with the fact that she has an early morning delivery mid-week. Perhaps the pickers, packers and delivery people are less busy at that time?