I believe it was Sea of Sorrows for me. The first time I contacted them asking what was up, since I wanted to read the book I had purchased earlier that year. They "gave" it to me as a "one time exception."

I never purchased a digital book again. Though I did still contact them again later that year, asking why it was gone yet again.

They tried to give me a "this may be an updated version" and I was like "no, this is a fucking novel based on a video game, they aren't releasing new versions every few months like textbooks."