Ah, crap.
Well, it means you'll need to work in much brighter room light (while the screen is at its very lowest brightness setting) to achieve a visual match. Can you increase the brightness of your room lighting?
And it also means you have very feeble basis to complain about this recent collage print. If you can't honestly claim that your previous prints match your screen, it's going to be a hard argument to mount. However, you should still contact them, of course, and see what they say.