Journal editor does not appear to pursue report of self-plagiarism This is a follow-up to an earlier question about a case of blatant self-plagiarism, following which I contacted the editor of the concerned journal. 

The editor did not acknowledge my initial report. It took a polite follow-up email about a month later before I got an answer saying that they were looking into the report and that they would let me know what they found. Since it is a blatant case, I expected that the investigation would be over pretty quickly. After I hadn't heard anything for about another month, I sent another polite email to ask about the status of the investigation. Another month has passed since then and still there has been no reply. 

I get the impression that the editor does not appear to pursue this case. Of course I know that the editor must be very busy, but I do not think it is unreasonable to expect something to have happened more than 3 months after the initial report. 

I tried to get in touch with the managing editor of the journal, but was told that the publisher will not provide the contact information. To put it mildly, I find this all very discouraging. I expected that reports of self-plagiarism would be taken more seriously despite the offence not being as serious as plagiarism or fabrication. 

What should I do next?
One other option is to go public (as jakebeal mentions in his answer to your previous question). I would suggest a step in between in which you would send another email to the editor stating that you are disappointed with the lack of progress as well as with the editor ignoring you, and letting them know that such unprofessionalism lets you with no other options but to let the public know.

Should they again fail to act and depending on your time/effort you are willing to invest, take the next step. My next step would be informing the institution of the self-plagiarizing individual about the whole situation. If you again hit a brick wall, you still have a nice story (self plagiarization and cover up by journal and institution) for some journalist, blog, higher institution, etc. (I guess you'll know best who to inform)