Not a hymn book, but I had a book pre-ordered on Amazon for delivery in October. When the due date came, they said it was not available and they could not give me a date. I'd had this on other books and the delivery had then appeared within days. But this time it stayed in this state, and when I realised it was in stock everywhere, and going to the Amazon page for it showed it as available from Amazon, it was clear they were not going to sort it out - so I cancelled the order, and reordered elsewhere (at a higher price, of course...).
The idea that this is deliberate because they don't want to fulfil their promise of the lower price seems realistic, I fear.
Paul