I do find it annoying as heck when they substitute fabric without noting that this will happen.
One of the first BOM's I did was a Lori Holt pattern. Farm Girl, I think. There were several months sent with fabrics that were not only not Lori Holt, but not even the same color. I agree, BigButte, that some shops are making the kits up themselves and stick fabric they haven't moved in. Well, I was still working then, so I built up a little LH stash and used that, instead. I'm pretty cautious about where I order anything from now. Always look for better prices, but also look for reviews and specifics.