I believe you. But those are NOT legitimate publishers.
Vanity publishers are everywhere. And they are a scam.
In
traditional publishing (a model which is actually less traditional than self-publishing, but traditional publishing is what it gets called these days, so I'll go with that) the publisher pays the writer. Always, always, always, always, always. There are no exceptions to this rule.
For a new writer, the writer must write the book first. Then they must convince an editor at a traditional publishing house to buy the books rights (with or without the help of an agent--but definitely do your research if you decide to do an agent. Some of them are excellent, but many are scammers.)
Once you have an editor who has convinced their publisher to purchase rights to publish your book, you (or your agent, if you have one) negotiates with the publisher for which rights you will sell and how much and when you will be compensated for the sale of those rights. Many publishers these days are demanding huge rights grabs for very little money (especially with new writers). Which is why so many people (including many who had successful careers as traditionally published writers) are choosing to self-publish these days.
But if you are able to negotiate an agreeable rights sale with a publisher, the publisher then pays you, the author, an advance against royalties. (These days the advance for a new writer is likely to be very small. Likely less than $US5K. Maybe even $0 for a small press. Expect this. But if the advance is <$0, the "publisher" is a scam. Run away!) Often the advance will be split up into 3 parts: partial payment upon signing of the contract, partial payment upon the publisher's acceptance of the finished manuscript, and partial payment upon publication. At this point the publisher also assigns an editor to you, and you start to work with that editor to craft a mutually agreeable story.
The publisher is also responsible at this point for copy editing your final work, hiring a cover artist and designer, doing the layout, typography, assigning an ISBN#, and actually producing any physical copies of the book.
The publisher then sends your book out into the world via its distribution network. (This is the only real reason to use a traditional publisher. Their distribution potential is massively greater than yours, which means the potential for sales of your book is also much greater.) The publisher markets (or not) your book as they see fit. (Usually there isn't much marketing budget for a new author.) These days the publisher will expect the author do do some marketing as well.
Now that your book is finally out in the world, hopefully it will sell some copies. All of the money from the initial sales of your book will now go to the distributors and the publisher. Because the publisher has already paid you the author's cut of those books sales. (This is what the advance is.) Hopefully your book will sell well enough to "earn out the advance" (many don't though, so be prepared for that), at which point the author then starts to receive the agreed upon percentage of all future book sales (for the duration of their contract with that publisher).
At some point the publisher will decide to stop publishing your book. Your book is now "out of print". If you knew what you were doing when you signed the contract with the publisher, all of your rights should revert back to you soon after this happens. At which point you can then self-publish the same book yourself, or else try to find a new publisher for it.
In
self-publishing, the writer may do all of the work themself. Or they may hire contractors to do certain specific jobs for them. If the writer chooses to hire contractors, then the writer is paying out of pocket for the specific services that they contract out for. But the writer chooses the contractors (including choosing which services to contract out for and which to do themself). The writer approves the contractors' work. And the writer remains the publisher of the work. If the writer then wishes to sell their published work, they will need to contract out the distribution of that work. (Technically you could, as the publisher of your own books, simply sell them out of your own garage, or the back of your car, or through your own website. But unless you are already an uber famous person, this method would not net you enough sales to pay for the garage, the car, or the hosting fees for your website. So in practice you most likely do need a distributor.) The distributor takes a cut of the sales, and everything else goes directly to the writer/publisher.
In
vanity publishing, unscrupulous people take advantage of writers' desire to be published and naivety about the flow of money within the publishing industry by charging the writers a crap tonne of money, for which the vanity press then does very little work, if any at all. The vanity press doesn't care if your book is any good. The vanity press doesn't care if your book gets an appealing cover. It doesn't care if your book is widely distributed or marketed. The vanity press doesn't care if your book sells any copies at all. Because they made their money already out of the 15K you paid them up front.
Please see Writer Beware's article on
Vanity, Subsidy, and Hybrid Publishers for more details.
Writer Beware is an excellent website in general for learning about the fiction publishing industry, particularly in helping new writers to spot scams.