The first thing that you should do when you visit a site is find out who you are dealing with. The company name, registration number, address and phone number should be given either on an "about us" or a "contact us" or a similar page. If the information isn't there, you should not buy. For a large purchase, you should check to see that there are real people who will respond to real issues by, for example, asking about Christmas delivery times. If you don't get a good answer for this, then they certainly wont be interested in sorting out a faulty phone.