I have ordered from dozens of online shops and only ever had trouble with one. Turned out the woman got sick and hubby tried to step in and take over (not very well, sadly). Most places I've dealt with, they have a comments box and you can let them know if they are short what to substitute or to cancel that item, etc. A few of my favorites are Thousands of Bolts, Fabric Shack, Stitch-n-Frame, Quilt Fabric Closeouts, Over the Rainbow.

Before I try out a new (to me) shop, I will frequently email them a question to see how quickly I get a reply. If I don't get an answer within a couple of days, I shop elsewhere. I have found that the ones I mention above generally ship same or next day, priority mail. I usually have my order within 4-5 days and each has always been correct. Customer Service have always been helpful and friendly.