I hear what you're saying, and definitely agree that if everything we're hearing here is true then Lone Star needs to do the right thing. But in the case where I disagreed with Lone Star's grading, I didn't let it slide because the prices were good; I let it slide because some of the other books in that same order were significantly under-graded, and also because it just wasn't worth the hassle to return what amounted to a handful of dollar books that, to me at least, were still priced right for their actual grade.
And for what it's worth, my : Lone Star is, basically, a big box on-line retailer. Whenever I deal with businesses like that (for comics or anything else), my expectations regarding customer service are generally pretty low. That doesn't mean they should get a free pass to rip people off, or be unreasonable and unyielding when dealing with customers...but given the nature of their business, the huge inventory, the number of people who handle it, and the high volumes involved, I say you pays yer money and takes yer chances when ordering from them, and hope that the big selection and click-and-buy convenience outweigh the hassles when something inevitably goes wrong...
Anyway, good luck with the resolution. I hope they get it right for ya!