Q: What should I do if the editor made a mistake and then rejected my paper?

Thank you for your question. We’re sorry to hear that your paper was rejected. Here, it seems that while the editor did not notice that you had already replied to the peer reviewers’ comments, he/she believes that the paper is out of the journal's scope. Given that you had received some positive feedback after two rounds of evaluation, you can write to the editor asking them to reconsider the decision given this past feedback and the revisions made to the manuscript. If the editor, unfortunately, decides against reconsideration of the paper, you will need to identify another journal for submission; do pay special attention to the aims and scope of the journal to ensure they match the objective of your paper not just in terms of the broad subject area but also the specific aspect of the subject being dealt with. The following article describes how you can go about choosing a journal for your article: How to choose journals for submitting your paper.