Why do chapter titles not appear in my audiobook?

It's been weeks of back and forth between my audiobook publisher, ACX through Amazon, and Apple Books. When my audiobook appeared on the Apple Books store, the chapter numbers and titles were replaced with Track 1, Track 2, etc, instead of the numbers and names I submitted. I immediately contacted ACX, who assured me they would get on the problem. About a month later, ACX told me because Apple Books doesn't directly ingest the files they're sent, the track names can’t be updated on ACX's end and therefore I had to contact Apple Books about this.

I'm hopeful rather than optimistic that Apple will fix this problem now, but my question was and remains why was this an issue to begin with? For distributors as large as Amazon and Apple, I expected more than for a problem as avoidable as not listing tracks with the names they were submitted with. I have only asked that my audiobook appear just as I submitted it to appear, and it's now been a month-long headache, not to mention how unprofessionally it reflects on me the author.

[Re-Titled by Moderator]