Waiting on a phone

I was contacted regarding a contract - I took an Apple Iphone 4 on contract but the next day decided that I wanted the Apple Iphone 6 as advertised on the website. After sending e-mail and phoning - they still sent the Iphone 4 and I declined the package when it arrived. A week after i app**** for the Iphone 6 I got a call stating that they have not yet received the Iphone 6 - needless to say I am still waiting. How can they advertise a product that they do not have in stock?<br>