This seems like textbook unauthorized commercial use of likeness, where both the "author" and (now that they've been informed and refused to act - and their business processes don't even appear to allow them to recognize unauthorized commercial use of likeness) Amazon are involved.
Next step should be your lawyer sending Amazon legal department a polite "stop fucking doing that right now and take steps to make sure it doesn't happen again now that I've brought this to your attention" piece of snailmail.
I'd suggest authors pile together with other authors in their state/country to hire a PR person or lawyer to draft letters specific to their region.
For extra giggles, have everyone send their demand letters to arrive in the same few days.
Here's a protip, folks:
Customer service reps are paid a fraction of what corporate lawyers are, are shielded by phone systems designed to make you waste your time / go away, and they have no obligation to respond or follow up to you. They're literally a "go away" droid army for the corporation.
Chances are the corporate legal folks are paid at least as much as you are, likely a lot more. And when you send them something, someone pretty much has* to read it. And if the letter ends with something along the lines of "I'd like to try to work this out without resorting to legal action", they've got to send at least some sort of response. Otherwise, you can file suit and say "gee judge, we tried to resolve this but they wouldn't even answer us"...and now they're already on the wrong foot with the judge for ignoring you, because judges really want people to at least attempt to work shit out before coming to court.
If you make an honest effort trying to resolve something (documenting all the way), stop wasting your time and hire a lawyer, or send the letter yourself. You merely need to be polite, state the problem and how you were harmed/damaged, and say something about desiring to resolve things without legal action.
* to head something off at the pass: yeah, it's probably a legal assistant or paralegal, not full blown counsel, at least in the early stages; still paid a lot more than a phone support droid. Also, the corporate lawyers might be an outside firm, and said firm might be getting paid a fixed contract price. You might not be running up the bill for BigCo, but every bit of BigFirmCo's time that you use, that's less profit for them, and increases the chances BigCo's contract goes up next year, or they get dropped as a client.