Amazon Prime - wrecking the brand proposition

Amazon are tricking customers into signing up for Prime when they don't intend to. So whoever has been given the task of maximising Prime uptake is wrecking the idea that Amazon is simple and reliable to deal with. What do Amazon think they are playing at?

Here is the feedback that I sent them after being tricked into "signing up" for Prime when placing an order.

I understand that you are keen to sign people up to Prime. But you have gone too far. Elsewhere on the site, Orange buttons are the easy option - if I want to do what Amazon wants me to do, which sometimes is what is in my interest and sometimes not. But I understand that. Grey means an option that I may want as an alternative to Orange. Except on the delivery page, where you sneakily make Grey another "do what Amazon wants" option.

To avoid joining Prime I would have had to spot that I needed an uncoloured link. Having made the mistake that you wanted me to make, you then offer no Back or Undo option. If I try to log in and cancel Prime immediately, I cannot - because it is apparently too soon to do so.

As a method of maximising Prime uptake, it is clever.

But as customer service from "Earth's Most Customer-Centric Company" it stinks. It means that I don't trust you - all your hard work in making Amazon the easy-and-quick option is undone because I have to check every screen to make sure that you aren't trying to trick me again. Completely dumb.