How do I recover a purchased Book that disappeared from my library?

I bought a book on 7/4/23 and have enjoyed reading it often. On 4/6/25 the book was no longer in my library. I checked hidden, and I hadn't hidden it. I confirmed I had paid for it, that it wasn't a free book. I have attempted twice to contact support, because I am hoping to get the book back, and if not, get a refund. I have yet to hear anything. Any suggestions?

[Re-Titled by Moderator]