Ripped of by online shopping

I ordered an item from Edgars online as a gift. When I received the item, I noticed that I was sent the incorrect product. I called the call centre three times now and each time I was told someone will call me back. I eventually received a call almost a week later and was told that the reason that I received the wrong item was because the wrong SKU was captured on the Edgars website and that I could not get the correct item because the call centre agent did not know the SKU of the correct item.

I am not stuck with an item I did not order. Why does Edgars offer online shoppin if they are going to send customers incorrect items with no way of exchanging.