I disagree, there are such things as false advertising and misleading advertisement in law. In addition, saying a product works but it does not at all is also argueable in court. Malaysia may not have it does not mean other countries does not have it. Unless they can argue is puffery.

It's called Trade Practices Act in Australia, breaching them means the customers can bring you to court. Usually customers get free consuling and free lawyers from a consumerism organizations. In Malaysia however companies are protected, in other countries the people gets the protections.

One of the legal way to do it is to say, items are on sale starts from certain price to certain price.