I believe a publisher is infringing copyright when reproducing a figure I created. What can I do? A few months ago an Elsevier representative contacted me asking for permission to reproduce one of my thesis figures in one of their books. Since this figure is only in my thesis (introduction section) and is not published elsewhere, I retain full copyright.

Because I am truly concerned about the negative effect of Elsevier policies on science at large, I am boycotting Elsevier. I considered not granting them permission, however I thought that this would mostly affect the authors of the book and have very little effect on Elsevier. I asked my Facebook contacts what I should do, and one of them proposed a very nice solution. Basically, he suggested that I publish the work under some terms so that everyone, and not only Elsevier, can be directed to the specific conditions under which this work can be reused. So I posted my figure on Zenodo (this actually makes sense because I have been asked many times for permission to reproduce this figure - mind you, that's the only reason why my thesis gets cited at all).

I replied to the Elsevier representative referring him to the Zenodo entry, and specifically letting him know that the modified version of the figure that they want to use does not comply with my terms (since it removes the text stating I own the copyright).

Last week, I noticed that a preview of the book is available in Google Books. To my surprise, I noticed that the version of the figure (fig. 11.1) that they ended up using does not comply with the terms I communicated to the Elsevier representative. What can/should I do about this?

Edit

I contacted the Elsevier representative who apologized and corrected the image. The Google Books link above now shows the copyright notice as it should (hopefully this settles the nonsensical debate initiated by @user71659 depicting increasingly weird scenarios in which Elsevier had recompiled the figure from scratch).
You attempted to use a crayon license, that is, modify the terms of an existing well-established license to better suit your needs.
This is frowned upon, because it can cause legal complications. In particular, the license CC-BY-NC 4.0 license that you attached to your work states

The Licensor shall not be bound by any additional or different terms or conditions communicated by You unless expressly agreed.

or, in other words (human-readable version on their website)

No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.

The CC folks officially forbid you from using that name and logo if you do modify their terms:

Can I change the license terms or conditions?
Yes—but if you change the terms and conditions of any Creative Commons license, you must no longer call, label, or describe the license as a “Creative Commons” or “CC” license, nor can you use the Creative Commons logos, buttons, or other trademarks in connection with the modified license or your materials.

So it is going to be difficult to argue for your additional restrictions in court. They are likely to be void. For legal purposes, we can assume that your work is licensed under an unmodified CC-BY-NC 4.0.
Notice 1 still stands, because the CC license allows you to specify your preferred name and wording for the attribution (and it seems to me that they complied with it in the book). Notice 2 is void. Notice 3 still stands, because the license only covers non-commercial use.
So Elsevier is infringing it because they are using it in a commercial work, right? In principle yes, but you wrote that you had an exchange with them and essentially authorized them to use it in the book under the terms listed in Zenodo. We would have to review your full conversation with Elsevier to see what you really wrote to them.
Disclaimer: IANAL.