Public domain images sold?

[aartturi]

Hello, years ago I created this image of balloons and uploaded it to Pixabay website. I was not able to remove it from pixabay, so I guess it for ever will be public domain, but now it seems to be sold here in Adobe Stock made bigger artificially.
Nissan photos, images, assets | Adobe Stock

My Pixabay profile link
Balloons Heart Sky - Free photo on Pixabay

So is this against of any rules? What if I myself render the same image again with bigger resolution, will it be removed or allowed? 

[Test Screen Name · Accepted solution]

Do you mean that it is sold in Adobe Stock, but you did not put it there? Normally there is a very clear way to make a legal complaint, but did you explicitly put it into the Public Domain? 

The Pixabay license seems simple and clear. It is NOT granting public domain. I don't interpret it but I quote selectively here:

"What is allowed?
✓ All content on Pixabay can be used for free for commercial and noncommercial use across print and digital, except in the cases mentioned in "What is not allowed"

....
What is not allowed?
This section only applies to image users and not to the appropriate image authors.

✕ Don't redistribute or sell someone else's Pixabay images or videos on other stock or wallpaper platforms."

If someone else is selling your (not public domain) work through Stock here is where to complain using the legal DMCA tool. A copy of your complaint is sent to the person who claimed (to Adobe) that they had the full rights to license it.  https://www.adobe.com/uk/legal/dmca.html

[aartturi]

Yeah, I didn't myself put it here, but I believe that years ago when I uploaded the image to pixabay, it used to be public domain. I think the owner changed his service rules later when he figured out that other similar services are just bulk copying stuff from pixabay to create their own "stock agencies". However, I cannot now very well check the original licence from wayback machine, because I'm on mobile and in middle of forest.

But the pixabay licence also says that "Don't sell unaltered copies of an image. e.g. sell an exact copy of a stock photo as a poster, print or on a physical product."

He altered it by scaling it bigger.

[Abambo · Accepted solution]

He altered it by scaling it bigger.

By @aartturi

That's not enough to make it an artwork on its own. It's derived work where the copyright is still with the original owner. File a take-down notice.