Each journal/publisher has Appeals and Complaints in Editorial Policies.

Link follows for Springer: https://www.springer.com/gp/editorial-policies/appeals-and-complaints

"The below procedure applies to appeals to editorial decisions, complaints about failure of processes such as long delays in handling papers and complaints about publication ethics. The complaint should in first instance be handled by the Editor-in-Chief(s) responsible for the journal and/or the Editor who handled the paper. If they are the subject of the complaint please approach the in-house publishing contact. (Please check the contacts page on the journal homepage. If no publishing contact is identified send the query to [email protected])..."

There are also some related research questions at Researchgate:

https://www.researchgate.net/post/How-to-file-a-complaint-against-the-editorial-staff-of-a-scientific-journal

Of course, you may complain to DOAJ.

Fostering trust: What we do

"At DOAJ, we work actively with the community to improve standards in scholarly publishing and to support editors to improve the quality of their journals. Together with COPE, OASPA and WAME, DOAJ is an author of the Principles of transparency and best practice in scholarly communication. We recently launched the Open Access Journals Toolkit with OASPA to support open access journal editors...

One important step we have taken to safeguard and maintain the quality standards of journals included in DOAJ is to develop a dedicated quality team. This group works to investigate suspected instances of questionable practices, which have been flagged during the application evaluation process, or by members of our community. The team examines editorial board composition and competence, and checks peer review practices, published articles and a number of other factors. As predatory practices continue to evolve, our investigations are becoming increasingly complex, and we sometimes consult external subject matter experts for their advice. In 2023 alone, we carried out a total of 409 investigations into journals and publishers, many of which resulted in exclusions from DOAJ of at least one year. These decisions are also open to appeal...

The future of trust?

Trust goes hand-in-hand with openness and transparency, and it’s vital that the community trust not only the journals in our index, but also our organisation and the work that we do. We aim to be as open as possible, and like many other organisations have made a commitment to the Principles of Open Scholarly Infrastructure. Our criteria, list of journals added and removed, and finances are also openly available...

DOAJ is only one part of a wider network of organisations working to uphold trust in scholarly publishing, and we are encouraged by the move to use markers of trust at all levels across the research lifecycle. Upholding trust is an ongoing process and a responsibility shared by all stakeholders; it needs a coordinated approach where everyone plays their part, from institutional training and support for ethical publishing practices in institutions, to increased transparency from publishers, and to infrastructures like DOAJ which provide metadata and standards..."

https://scholarlykitchen.sspnet.org/2024/06/06/guest-post-doajs-role-in-supporting-trust-in-scholarly-journals-current-challenges-and-future-solutions/?informz=1&nbd=6f03e560-5431-4744-8998-e00223ee7a82&nbd_source=informz

https://publicationethics.org/resources/discussion-documents/guest-edited-collections

https://blog.doaj.org/2024/01/25/weve-amended-our-special-issues-criteria/

https://doaj.org/apply/guide/