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When does a pricing error become false advertising?
It's definitely annoying, but it's not necessarily false advertising. There is no rule or law that says they have to fix a pricing error at all, let alone within a certain period of time. Unfortunately they have no obligation to do business with you unless they take (and keep) your money. If they canceled the order and returned your money you have no binding agreement with them.  On top of that, in the US... 'misleading advertising' usually refers to "Any advertising or promotion that misrepresents the nature, characteristics, qualities or geographic origin of goods, services or commercial activities" (Lanham Act, 15 U.S.C.A. § 1125(a)). The main criteria that they evaluate before taking legal action is whether or not someone has suffered harm or loss due to the reliance on the bad information. But you're in Europe. The EU ideas behind misleading advertising tend to focus a lot more on comparing one product to someone else's and making subjective claims or false promises. Pricing does come up, but still, you need to have an ability to prove that you suffered harm or a loss from the business' actions.  Even if you were able to prove that, to force the business to change its price catalog, you would need to go through legal proceedings, demonstrate the harm that you've sustained, and then have a judge decide in your favor and order the supplier to comply. My guess is that it's just not worth it for you, but you haven't specified if this is just an annoying shoe-shopping experience or if you are regularly experiencing bait-and-switch tactics from a supplier that is a crucial part of a business operation.  If it's the former, just like a physical shop reserves the right to kick you out if you're not behaving, (but usually doesn't because they'd like to keep you as a customer), an online shop can update its prices whenever they like. They can change their prices too, and cancel orders.  If it's the latter, then start putting together some documentation on how many times this has happened and how it has damaged your business. But before you get on the warpath I would recommend you look for another place to buy whatever you have in mind, or else try a pound of sugar in your approach to this supplier... My own business experience has shown that can go a lot way in figuring out a mutually beneficial resolution. If you want to see a bit more...  Here is the EU Justice Commission's website on false advertising, Here is a PDF leaflet from the UK Office of Fair Trading that spells out what is explicitly not allowed from a business by way of advertising & business practices.