False Website Information

On the 24th November I ordered some goods from Makro Silverlakes using their online web system and according to the information on the website it was suppose to take them 2 to 5 days to deliver, I waited for 15 days for my order to be delivered after such a long wait I was told they do not have a stock for my order and they are going to pay back the money. My problem is that why must it take them 15 days to realise they do not have the stock, are their system poor enough not to notify their stock levels or was this done intentionally just to delay me from getting my goods elsewhere? What they did was unprofesional, I will never trust that store ever again.