Promotional items out of stock

When i received an emailer from Zando that they had a 50% sale of shoes i was very excited. I logged on to the website and saw the white mens Adidas superstar on sale for R499. When i clicked to purchase the item it showed there was no stock or any sizes available which is totally unacceptable for a company of your stature that promotes these online sales. Nobody can tell me that within the same hour of the sale the stock is sold out!! When i check on your system to purchase this shoes it shows you have in stock but just not on sale anymore. This makes me think that you running false advertising campaigns misleading the public that you dont have stock when in fact you do!! Please i need an answer. I even phoned the customer services helpline who confirmed that they do have stock but its back to the normal price when in fact it was advertised on the site for R499 but when i clicked to order it suddenly dissapeared from the sale item list. UNACCEPTABLE!!!