Advice, please?

[bladebandit.livejournal.com]

EDIT: Ok, thank you for all your advice and comments! Will post a beware up ASAP.

Just a little thing: I need some advice.

In my TOS, I state that I only allow commissioners to re-post artwork to their FurAffinity galleries (Basically because I like to know where my work is being posted). I'm happy to make exceptions to this of course, but only if people ask.

A past commissioner of mine (Who was incredibly rude throughout the entire commission process; and that should have been warning enough...) has been banned on FA for art theft/ban evasion. They had access to my e-mail address, yet they have re-posted my piece on InkBunny and SoFurry without my permission. I kindly asked them to remove the images on both websites as I hadn't given them permission to post them there.

They deleted the submission, but reuploaded it. Here's something they wrote:
"I have permission to upload the art. the artist did not give any limits on WHERE.

since I did my end of the TOS. and he kept his. this is my fursona, and I paid good money for it. if he's not letting me upload this on MY pages...I'd want a fuckin` refund."

(I can post a screenshot editing out their username/userpic if it's needed!)

Basically my question is does their behaviour warrant a beware? Should I just ignore it and leave them be? I really don't want to deal with them/can't be bothered with them, because they're such a nasty person.

It's not even a huge situation; just wanted to be sure I was handling it correctly, really!

Thanks in advance!