However, by Monday morning more than 200 customers had taken to Big W's Facebook page to complain that stores around Australia had run out of the book almost instantly, and were told they would have to wait until stocks were filled, at which time they could buy the book for the recommended retail price of $45. Big W customers around Australia have complained about the sale of the latest J.K. Rowling book, Harry Potter and the Cursed Child. Credit:Graham Tidy Some customers have said they were told the book would cost them $45, however Big W has since said the advertised price after the sale was $20. "There are not enough words in the English language to express my disgust and anger with the totally unconscionable and unethical behaviour of your business in advertising the latest Harry Potter books for $15, despite being fully aware that they would sell out in minutes," customer Mason Blunt wrote on Facebook. Customers complained that stores were not sufficiently stocked to meet demand, with some stocking fewer than 50 books.

"I'm sorry, but what on earth were you thinking only sending 42 copies of the Cursed Child to Big W Yeppoon?!" customer Carolyn Booth wrote on Facebook. Embattled Big W chain is facing more upheaval as Woolies is working to turn around its fortunes. Credit:Glenn Hunt A Big W spokesperson said the one-day special launch offer was clearly identified as "while stocks last" via print and online catalogues, but added that "social media channels did not carry this message and we are reviewing our internal processes to ensure terms are consistent across all platforms". "Customers should be aware that we have additional limited stock arriving this week at the discounted price of $20, as advertised. We continue to seek further stock from the publisher but no further stock is yet available, again due to unprecedented demand for this new play." People gather for the release of the new Harry Potter book, Harry Potter and the Cursed Child, at Dymocks in Sydney. Credit:Wolter Peeters

On the Gold Coast, a law professor who was affected but asked not to be named, said Big W's actions "violated the Australian Consumer Law bait and switch provisions". "There was no indication on the cover of the Big W [magazine] or Facebook page that there was limited stock ... except for one small asterisk inside, in six-point font that it was 'while supplies last'," she said. Promotions for the $15 sale of the book on the Big W Facebook page. At the Big W store at Burleigh Stocklands shopping centre on the Gold Coast, she was told the store had received only 150 copies of the book and had a policy not to provide rain checks. After leaving a public Facebook post complaining and messaging the store directly, the customer said she was told on Monday that she could buy the book for $15.

According to the Australian Competition and Consumer Commission, bait advertising can be a legitimate form of advertising, "however, it is illegal to engage in this conduct where goods or services are advertised for sale at a discounted price, and they are not available in reasonable quantities and for a reasonable period at that price". A spokesperson for the ACCC said it did not have any specific comments in relation to recent matters raised regarding Big W. "If there is not a reasonable chance that the offer will be available at the advertised price, a business may be in breach of the ACL unless it promptly offers a 'rain check', an acceptable substitute product or take other corrective action," she said. Loading "The ACCC would be concerned if errors in any representations made to consumers were likely to be false, misleading or deceptive."

In Sydney, Potter fans lined up for up to 2½ hours at the Dymocks bookshop where the book retailed for $29.99. Latest consumer news