Just got another reply from stores.ebay.ca/lecanvas
(the ebay store that is selling works by simply taking random artworks from the internet including mine).
Here's what he wrote:
I am the owner of this shop and all these images are bought or made by me and I take full responsibility for all of them.
Your image is on PUBLIC DOMAIN, you should know that and do something about it.
Made by you? Public domain? What? Since when?
When will the lies end?
Feel free to go through his ebay store gallery and see how many other artists you can find that are apparently "public domain" and "made by him".