Cancelled order without explanation

I bought a home theater system on aug/06 from sonystyle.com. the oreder was submit successfully and my credit card also was hold the money for it. on aug/12 the time already over the shipping date, I called to sony customer center to confirm my order status, they told me there is some problem with warehouse, but they promised that my order will no have any problem. after that, I recieved a email for order cancellation. they just cancelled my order without any reasonable explanation, they just said they are unable to give an estimated ship date???!!! what a ridiculous explanation!!! they even didn't apologize for what they did. Is this a big company's customer service???