My bank has an option to send me a notification every time I'm charged for something. I've noticed several bills that were higher than they should have been "due to a technical error". I'm certain some companies rely on people not checking and randomly add "errors".

Notably there's no way (known to me) that you can have direct debits sent as requests that aren't automatically paid. I think that would put consumers on an equal footing with businesses though, which is obviously bad for the economy.