My delivery last week was a complete shambles.
On Thursday, I had ordered some items for a Prime delivery on Friday. I had specified an Amazon locker delivery, as I was going to be in and out during the day, and the lockers are only 15 minutes walk away.
On Friday, I checked the order a few times during the day, to see if they had been delivered to the locker yet. They didn't turn up.
On Saturday, I got an email saying that the "Amazon Locker Artery is not accessible", and "We'll try to deliver your order on the next working day (Monday to Saturday)." So an order placed Thursday for delivery Friday was now going to be Monday.
Amazon were unable to improve the delivery or change the delivery address to my home. However, I discovered that if I created a new order for the same items for delivery to my home, they would deliver on Sunday. This I did; unfortunately, one of the items was now out of stock.
My second order arrived, next-day, on Sunday. On Monday, I was told that the first order had been despatched. It was available at the Lockers on Tuesday and is currently waiting there for the delivery to time-out and for Amazon to collect it again for a credit.
I made a complaint to them about it and got the usual apology and an extension of 30 days to my Amazon Prime subscription. It is always worth complaining of any delivery problems, as this is their standard response.
All in all, I am satisfied with how they handled it, after the fact, but at the time it was frustrating. The items themselves were minor but were needed to complete a bigger project that I wanted to work on over that weekend.