All they'd have to do is tweak their colour management to black and white specific, that's what I do on my printer now (Epson r2400) to get round any problems, and it works an absolute treat.
Printing onto photographic paper from negatives is a very different game to inkjet printing though dangleman and you can't just "turn off" the colour.
Basically, you print in either colour or B&W and each has totally separate papers and chemistry to process it in.
(As an aside and a fairly geeky one at that, does anyone know if B&W processes have a name like the colour ones do....E6, C41, RA4 etc?)
Colour printing from negs is all about balancing out the cast created by the film material itself. These casts are often there in colour prints too but it's less noticeable......to most folks anyway.
If you look at the negs you get from these b&w films that go through a colour film process (that's the one called C41 btw), they do usually have a pinkish tinge to the film material. This is totally normal and when you stick this film in an enlarger and print onto real b&w paper, that colour cast is ignored.
When you place that film through a normal minlab machine churning out colour prints (that's the RA4 process for anyone collecting geek points), that pinky tinge is reversed out to a green cast. Given to a good printer, it's easily removed and a neutral b&w print is totally achievable. It does take time though and time is money and your not paying for that kind of service with a jessops d&p.
I've always considered those sorts of prints to be nothing more than a proof or contact sheet service to see which shots are worth actually printing.