What a bananas thread. Makes for interesting, if not entirely pleasant reading, that's for sure. Some startlingly immature comments made all around, as well. I thought we were better than that, TB!
To me, it sounds like both parties in this discussion have made mistakes. OP, you definitely took a serious chance by buying sight-unseen, and trusting a company's website "guarantee" jargon as anything other than gussied-up advertising. Especially with it so clearly stated that there is a strict no-return policy.
But also, this return policy seems really odd, possibly a little shady, and definitely one that is going to create unhappy situations like this. Assuming the OP has told the truth about his CS experiences (and I have no reason to doubt him on that), Kiesel has handled this situation rather distastefully, although seemingly within their legal rights to do so. And yeah, I can't imagine they are going to go about diagnosing the bass-in-question with any degree of urgency now that the CC company has been involved. Although, again, based on OP's description of the situation, it sounds like they don't particularly believe there to be anything wrong with the bass in the first place, which absolutely does not bode well for a happy outcome of this factory visit.
I don't really see any outcome other than a negative one for OP at this point. Either you'll have to sell the bass, probably at a decent loss, or else put more money into trying to make it more how you want, which may not even be successful. FWIW, I would definitely like to hear some sound clips...
Not that I was likely to ever be in the market for one of their instruments, but there's absolutely zero chance of me giving Kiesel any business now. Despite the buyer's mistakes, there's absolutely no excuse for bad customer service!