Sorry for your misfortune, however you can't assume everyone thinks like you, or lives by your standards. I'm sure that every seller does not look at Audiogon's grading scale before listing a product. This would result in different ratings from different people for a product in the same condition, not to mention that some stretch the truth, and others are more conservative.
IMHO, when you buy something, it is your responsibility to know exactly what you are getting, even if it means being "picky". If you think the seller lied or misrepresented, then start a dispute through Audiogon, otherwise, just move on, let it go, and chalk it up as a learning experience.
Though hard to do, I force myself to think about this old saying at times,
"Problems have only the size and weight that we give them."
Hope you have better luck in future transactions.