Except that just bloody near every online retailer uses rent-an-IT-guys or scripts from dubious places. I don't know why. They don't cut corners on anything the upper management thinks is important, but God help us, when it comes to actually paying for someone to do their IT work ... "oh, we can outsource that" and they do, to the lowest bidder -- or to someone's nephew. Of course they shouldn't. But that doesn't seem to slow them down. (I once had a very nice gig consulting for a place where "Joe knew this guy..." fixing the messes that "this guy" left, until they got bought out by someone more willing than Joe to get a server that wasn't older than some of the interns) It never ceases to amaze me ... they'll buy solid gold faucets for the executive washroom, but actually paying someone to build their website? To write their scripts? To make it all
work? That's needless frivolity.
So, while I agree that Kobo should have a script that doesn't allow the user to buy something twice, slacking in that area seems to be the industry standard. It's one of those cases where a company would rather fix a problem than not have it in the first place.
And, in this case, they did fix the problem. They canceled the spurious sale. They even gave the customer a free book by way of apology. Most people (and their mothers) would be happy with that. It's when someone comes here trying to gather up a mob to march on Kobo HQ with pitchforks and torches, or at least to send strongly-worded emails, to demand a free $50 in addition that I get peeved.
Also, you pushed my "rant about idiot website owners" button, and it may take me a while to run down.
edit: "Joe" is not the real name of the guy in question, just in case it wasn't obvious.