Just had my first unsatisfying interaction with Amazon customer service. We've had a few items come a day late recently, and I haven't complained. But I bought something that was supposed to get here Tuesday, isn't here yet and there's no option to see tracking info like there usually would be. Online chat worked well for me in the past, and I was watching a show with the wife, so I went that route. The agent basically just said sorry, it should get there tomorrow. She made me complain about it being unacceptable and that I probably would have bought it somewhere else if I had known it would have taken this long. She just said sorry again and sent canned explanations about the shipping process, different shipping options I might have chosen, how the item has to be in stock otherwise the date given to me would be later than 2-day, how they might have had to wait for the item to arrive to them first, etc. None of that applied to my purchase, which was "fulfilled by Amazon", marked as in stock, and I was given that guaranteed date at checkout. After I pointed that out, she finally offered 20% refund - it was only a $13 item, so not much (and I wasn't expecting much), but that wasn't really the point to me. In the past, they've been quick to offer something more than "sorry about that" before you complain more than you already are by contacting them.
I guess I might just have been spoiled with my interactions in the past, but they're slipping a bit.