I expect Mongoose did repsond promptly. I also expect that Amazon wouldn't respond, at least not in a way thatanswers your question, but like I said, Mongoose have no control over which edition Amazon sell you unless they do a product recall, which I don't see happening, or think should happen. You seem to have been gipped by amazon in this case, and, at least under UK trading laws, I see no legal entitlement to a refund or replacement of your purchase as unless it was advertised on their website as the Atlantean Edition, then you got what you paid for. Of course your Canada's laws may be different in this matter, and of course Amazon may go above and beyond the legal requirements.
LBH
(I like buying books in person, or when I'm sure which edition I'm buying, which is much easier in person)