Alright, so it's a mishap.
It also highlights the weaknesses of this sort of service, where you hand over payment details to be used any time you click a button or other, or even if some faceless clerk elsewhere hits a button or other. Where they're making nice and Stuff, they also could've "forgotten" to send you that email at all and just started charging. The big advantage of taking cash to the corner shop is that it has to pass your fingers, as in you *know* you're paying. Electronic payment has no such clear "payment point" as happens when you pass some coins or notes to a merchant.
It's one of the reasons various parties keep coming up with ever more fancy electronic payment methods. It makes it harder to track your money, and people not paying attention to their money are easier parted from same. For electronic money transfer to not become a scourge, we'll need to fix this. Somehow.