Unless your phone was "hacked", the only thing that can be saved from any website directly to the iphone is a picture. Hacked phones, on the other hand, are vulnerable to being attacked. So, if your phone has the stock firmware on it, you have nothing to worry about, even if the site in question is fraudulent. Nothing can be installed or downloaded to your phone. As I said, you can save a picture, but that's it. If you go to a site & suspect it is fraudulent don't enter ANY personal information, if such is requested. In your case, why not call O2 customer service to verify the authenticity?