This is quite unlike the Fuji situation where we were pushing at an open door. The Jessops door is firmly locked. Reminds me of the old song, a line of which is "I talk to the trees but they never listen to me". About the same chance with Jessops. Alas song lyrics always give away one's age.
It may be my imagination but Jessops now seem to be staffed by personnel under 30 for whom film is an alien product and any inquiry on said subject is met with a similar response to that which you'd receive if you went into a TV store and insisted on a B&W tele. There really is no turning the clock back for Jessops which is how they'd view supporting film.
My advice would be to take advantage of any fire sale you see in a Jessops store with regard to film products and just call it a day.