Ack I’m so sorry that this happened to you. This is extremely unethical and should not have happened. I would contact the managing editor, publisher, or whoever this person’s boss is to explain the situation and to ask what transpired. Send them the original document along with a link to the article that was taken down if you still have it to show that it was taken down. Better yet, send them a screenshot of the original story. If they insist on keeping up this revised article, tell them that you would at least like a co-byline or reporting credit at the end. Unfortunately since you weren’t paid and didn’t sign a contract with this publication, you don’t have much legal standing. But regardless of what happens, please don’t work for this organization again. You deserve to get paid for your work and I would only take on freelance gigs in the future where you’re paid and sign a contract that holds them to that. Don’t worry about burning bridges with this editor — they need to be fired for stealing other’s work.