I contacted Midwest and NB awhile back to ask if they would double-crush my grains for me (I do BIAB). Both said they could not, as they don't do custom crushes. I understand why--imagine the hassle if every order came with a specific crush. So I go to my LHBS and double-crush it there. I wouldn't be surprised if they ignore your request for a fine crush.
If you don't have a LHBS close by, I'd second the suggestion to get a mill. Then you might repeat one of your previous brews, keeping the process as close to original as possible to minimize variables, and compare results. Heck, post pictures here of your crush and see what the good folks think. If you still have an efficiency issue, then you have at least eliminated one variable.