Thanks for the advice. I'll do the RA thing.
The two past purchases that I had VISA look into were cases where I canceled services which I'd been paying for and the billing continued.
In this case, I didn't do my due diligence researching the item before ordering it and when I did, it was after-hours and I couldn't cancel until this morning. So, yes, my bad as far as that goes - but not fickle, and not a douchebag.
But if they charge me a re-stocking fee (they advertise "No questions asked, full money back guarantee if not satisfied", I'll definitely contest that.