Advice for legal action in regards to a website selling my art without permission?
EZCosplay.com took my template for the Hashiyan Matryoshka (an extremely popular cover of a Vocaloid song) hoodie and is selling these cosplay hoodies for $70-$90 without ever contacting me. Granted, I posted the original template on Deviantart.com in 2011 for people to use freely, I never expressed any permission to use it for sale, especially not a well known cosplay website.
Can any artists or law people advise me on how to approach the website about this?
Here's the link to my original upload of the template:
http://root-for-theunderdog.deviantart.com/art/Hashiyan-Matryoshka-interface-217089010
And here is their website and item image compared to my template:












