It has been asked before if it is ethical to withdraw from one journal, from which a paper has been accepted, and resubmit to another better journal. I believe that the situation here is a little bit different.
I submitted an article to a Computer Science conference in which the organizers stated that the proceedings were going to be published with publisher X, that is indexed by Scopus and Scimago. I personally checked up if that publisher was on those indexing sites, and it was true; so far so good. So I submit a research paper to that conference that got accepted and in the acceptance letter they put again that paper will be put on the proceedings published with publisher X.
A few days after my notification letter, I checked up again at the site and saw that "misteriously" they have taken away the note saying that they will publishing with publisher X, to put that they will be publishing with another publisher X. When I checked it up I saw that the publisher Y is not indexed on Scopus, or Scimago, but only by Google Scholar, DBLP, EBSCO, DOAJ, and ProQuest.
I have also seen in the webpage that publisher X has put the following message on their news site:
Please be aware that there are conferences claiming to be associated with X, despite having no relationship with us whatsoever. X attaches the utmost importance to standard and quality of publications. If you are aware of any such conferences, or suspect their authenticity, please contact us at xxxxxxx.
Personally I feel like being cheated. I mean, I have spent time and financial resources for trying to reach the deadline, and now this conference has just changed the rules without giving a notification to anybody.
Long story short, I have seen other conferences that are really sponsored by publisher X; and the question that I have is if I should resubmit my research paper to these other venues? I have still not paid for the registration part, I only got the acceptance letter. Also one funny thing is that this conference put a document of copyright transfer, which was the format of publisher X, but since publisher X has informed that they do not have any relationship with this conference I did not sign any document.
In the conference site they have put the following (I put it here for clarification purposes):
To be published in the XXXX Conference Proceedings and submitted to X, an author of an accepted paper is required to register for the conference at the full (member or non-member) rate and the paper must be presented by an author of that paper at the conference unless the Workshop Chair grants permission for a substitute presenter.
Actually publisher X has put a list of conferences that are misusing their name (this was recently posted a few days ago), and that conference is pointed out in that list.