Don't ever buy a phone in store from carphone warehouse as despite saying you have 2 weeks to change your mind, if you upgrade with O2 they refuse to do so. They don't respond to complaints and totally ignore their customers. I bought a Samsung Galaxy 6 in Salisbury, I was not sure about it as I had always had an iphone and although the salesperson knew this she didn't tell me I wouldn't be able to change it. I went back to Barnstaple 2 weeks later as I wanted to change back to an iphone but was refused. O2 said I can but carphone warehouse say I can't. So I have a 2 year contract with a phone which I don't want and having complained and telephoned them 3 times no-one has bothered to get in touch. Customer service non existent! Avoid using them, may appear to be cheaper but big mistake to fall for it!