Unfortunately that happens and even when they are standing in front of you cutting. We are bless here to have an LQS only about 25 minutes away and they are wonderful. Doesn't matter what you buy they will often give you whats left on a bolt for free when they cut. I've only purchased a handful of FQ last year and that was at a Walmart in that town because it was pretty decent quality and alot better than what they have at the Walmart in my town and only because the prints and colored were unique and those were cut fine.
I mostly buy at minimum 2 yards of any fabric and more often at least 5 yards or bolts because I know I will make good use of it down the road.
I agree with what someone else stated regarding FQ's that they are not all equal in quality and buying certain brands is usually better.