Cyber Monday online

On Monday my husband purchased a pair of takkies online at Sporstcene for Cyber Monday half price. A confirmation email was sent to him to confirm his order and payment thereof. On Wednesday he received an email to say his order has been cancelled due to the item being out of stock. I find this totally unacceptable as the item was in stock at the time of placing the order. They cannot just give you a refund and expect you to be happy. They should give you an option of taking something else at half price because of the inconvenience they caused you or give it to you at that price when they receive stock again.