Finally, I have managed to buy tickets to see the film at Showcase, Nantgarw (near Cardiff.) Iknow I'm a bit slow, but I was clicking on the cinema's 'Book tickets' button wondering why nothing happened. This morning I noticed there was another button next to it for MovieTickets.com. I clicked on it. It seems you have to book tickets through this site and not the venue's own website. I wish that had been made more obvious, for those of us who are old and a bit dim!