not cool at all, this happened to me a few times back in the day, cant believe this still goes on, i am sure all the artwork on this site is stolen, just report it to your fanbase not to go to that site and stay away from it, if you can find the other artists there you can probably do a social media blitz on them and show their true face.
good luck!
I send an email and if they don't respond I will go put it on other social media. What did you do about it? I see art often get stolen on FB "fan" sites trying to sell it and always contact the original artist...