I reported plagiarism to a questionable journal. How long should I give them to amend? I recently sent the following letter to a journal of questionable reputation:

To whom it may concern:
In the [Journal Redacted], in the paper titled [Paper Redacted] by [Authors Redacted], the following section is plagiarized from Wikipedia:
[Text Redacted]
That section is copied from this Wikipedia article: [Link Redacted]
Thanks,
[Signature Redacted]

They replied with the following:

Dear Mr. [Name Redacted],
As you mention that there is plagiarism. Yes, I read the research again but that part is from introduction. Introduction part is not part of the research.
Please read it again...

I replied with:

Sir or Madam,
You are correct that is from the introduction, but any usage of non-original material whether part of the research or not must be properly cited or it is plagiarism. Even if this were an opinion piece and not research, this would be plagiarism. I expect this will be addressed soon.
Thanks,
[Signature Redacted]

They replied with:

Dear sir,
I will inform to author for proper reference citation of the paper.

What do I do at this point? If they take corrective action, it will take some time. How much time is it appropriate to give them before I report them elsewhere?
The responses that you received from the journal show that it is not just questionable but clearly predatory and rubbish. No sane scientific publication venue would say 1) wholesale plagiarism doesn't count in the introduction and 2) it can be addressed just by adding a reference.

The journal clearly has no interest or intention toward rectifying the situation, and it's almost a pure waste of your time to interact with the journal more at this point.

At this point, there are two actions that make sense for you to do:


If it's a "pay-to-publish" open access journal, make sure it gets included in the predatory publisher list by contacting Jeffrey Beall
Report to Wikipedia, who can decide whether they care enough to pursue.


After that, let it drop: the internet is filled with vast sewers of low quality junk, both scientific and otherwise, and you've got better things to do with your time.