Whether there is value is entirely subjective. You don't want it and should be able to cancel.

If you have contacted NK as you have and the charge still came through, simply file a chargeback with your card issuer (bank) and provide a copy of your email or screenshot of your tweet ./ complaint form as backup. You should have a temporary credit within a day or two and that should become permanent within the week. Make sure that your chargeback focuses on the cancellation and not on your views of the product (which are irrelevant).

For $9, not worth your time or angst.