There's one class of privileged iPhone buyers who are going to get all of their money back: Those who bought the phone with an American Express card. Extending its usual price-protection policy, the card issuer is refunding $200 back to anyone who paid the old $599 price for an iPhone, blogger Muhammad Saleem reports. All they need to do is call customer service, he writes. (It's not clear what's going to happen to people who bought the cheaper 4GB iPhone, since that was discontinued, rather than reduced in price.) Some Visa and MasterCard issuers have 60-day price-protection policies on their cards, but for early adopters who waited in line to buy the iPhone on June 29, that window has already passed. Update: American Express apparently discontinued its price-matching benefit last year. Anyone else, like Saleem, luck into a generous customer-service rep? Another first-hand report after the jump.