Anyone ever ordered from Waterstones multiple books with different publication dates?

Hi! I made an order to waterstones a while back for multiple books with different publication dates (07/10/2024, 10/10/2024, 08/04/2025) and wasn't sure how Waterstones would be splitting the order especially since shipping was calculated as a total. Today (06/10/2024) I was just billed by Waterstones but the amount (£43.04) wasnt the same as the total of the order (£89.24) and I cant seem to match the a book to the number.

Anyone would be able to explain how Waterstones preorders work please? And are they allowed to take more money than the total price shown in the order?