Learn to compromise. Editors can and often do change things. That's what they're there for. They catch the little mistakes we make (and we all make mistakes). They also may make changes that are better for structure, your audience, the web, and more. Though you may not always agree with their changes, you will have to deal with many of them. Depending on the publication, you may be able to form a compromise with the editor.
Let it go. That may be easier said than done in many cases. As writers, we see our writings as our little babies, if you will. We work hard on it and it means so much to us. Altering it can feel like someone is trying to change us. After all, it does have our names on it. But at some point, we have to learn to let it go. If the work never bypasses an editor, it may never get out in front of the audience. Try not to get too attached and let the work go once its complete.
What's the change? Instead of becoming to attached to the way the piece is written, focus on the message. If the edits do not take away the message, don't be so hard on the editor. It's perfectly fine to address the editor if you feel that the changes are unsatisfactory or take away from the message. But if the change is nothing that takes away the message, why waste all that energy getting upset? Write another article.
Report the editor. This is only for extreme cases. I say that because as a writer, you will need to learn to deal with the fact that your writing will be changed by editors if you want it published with major companies. If the editor really is making changes that are unreasonable (and not just changes you don't like - changes that affect the quality of the work significantly), that's when you report the editor. I advise not taking this route unless necessary because a writer and editor need to be able to work together peacefully. But obviously, if there is an injustice it should be reported.
Switch venues. If you just cannot deal with a particular editor, write somewhere else. Ultimately, you should be happy with your writing (or any) career. If that's not happening, you haven't found the right venue/s to write for yet. Realize you should not be switching venues every time you don't like what an editor does. But if there is a true problem, remember that you can move on.
Write for yourself. If you truly cannot deal with anyone at all messing with your own work, only wrote for yourself. When someone is paying you to produce work, it should be what they want, hence part of the reason for the editors. If you create your own venue, such as your own website or blog, you make the rules. Even if you go this route it can still be a wise move to have an editor or at least a writing buddy that is willing to be a second pair of eyes. But you'll have the most freedom when writing for yourself.
Bottom line: Editors are a part of the writing and publishing business and writers need to be able to adapt to that fact. Work with (not against) your editor, unless you have a legitimate claim against them.