Mathers of Lancashire do Delta 400 for 1.99 (24) or 2.59 (36) and, unlike 7 dayshop, their customer service is good and it's usually next day delivery.
Thanks for the link, I use SHD and Retro for most of my film- now I have another source .(I like the "of Lancashire" bit in the name - maybe It's the impending 50 but I miss seeing counties on addresses.)
As for the mag - I'm surprised AP knew what a film canister looked like !
AP isn't a bad magazine. There is still a lot of analogue stuff, particularly readers' photos & answers to readers technical questions. Also they publish every month or so an article on classic cameras which are very informative (particularly about what to avoid). The magazine is also worth it for the adverts, particularly for cheap sources of film. There are several others in addition to those already mentioned.
Realistically the magazine has to devote a lot of space to things digital or it would go out of circulation. The inclusion of a free film may encourage people to explore analogue photography and monochrome in particular. It's difficult to think of any other photo magazine that would include a free film these days.