Vodacom upgrade misleading advertising

I upgraded my contract with Vodacom on the 3rd of December. The website indicated that the phone I wanted was in stock and would be delivered within 5 to 7 business days. Upon following up 3 days after the order was confirmed I was told that they in fact do not have stock and that they are not expecting stock within the next two weeks. Considering that the upgrade was for my son for his birthday on the 14th December I am very upset. The consultant basically told me that they didn't have an ETA and there is nothing they can do. It's misleading to indicate upon checkout a timeframe when they knew they didn't have the stock!