Having to deal with copyright infringement is a frustrating and irritating dilemma to face. You work hard on your materials, designs, and products only to find that someone copied and is marketing your work as their own.
As a sales rep, I ran into this problem often enough. From dealing with foreign knock-offs to 
regional folks too lazy to come up with their own designs — I saw many ways producers dealt with the problem.
Carolyn Edlund, the author of the Artsy Shark website, addresses this problem in her post: How Artists Can Fight Copyright Infringement
Following are some of her main points:
Have you experienced intellectual property theft? Here’s what you can do
How do you find out if someone is infringing on your work?
Sometimes you can type the full description of a product from your website into a search bar, and see the offending copycats come up. That’s because those lazy parasites can’t even be bothered to change the marketing copy. They just use yours.
Or, type very specific keywords into search that you use to describe your art or items on your website. Scroll down and if your images appear on sites you don’t recognize, investigate further…
Check them out and take them down
Find out who owns the site in question by searching WhoIs, which can provide a name and email address to contact the owner directly. If they have paid for privacy, the owner’s name will be anonymous, but you can learn the identify of their domain provider, which gives you another avenue…
Gather proof
When you set out to fight the bad guys, you must have proof. Gather all links to web pages that display the stolen intellectual property (such as your art) and take screenshots that show clearly that they have infringed…
Exert direct influence
When you have identified an infringer and gathered evidence, you can often get results through direct contact. Send a firm but calm email to the website owner. As much as you would like to call them every name in the book or threaten bodily harm, you must take the high road (after all, you’re the good guy.)…
Call them out
There have been some high profile infringement cases where artists have called out offenders in public, such as this case in which the accusation went viral on social media. Public humiliation can be very effective. When an artist has been wronged, it naturally concerns other artists (who are of course also at risk) and they take up the cause as well. Nobody wants their dirty laundry aired in public, and proof of blatant theft can cause the cockroaches to start scurrying…
If you are facing this issue, I suggest you try the suggestions above (read the full article here) and/or contact your lawyer for their legal advice.