Our System is Not Responding

When logging on to AMEX, msg: "We're sorry..... The American Express Online Services system has not properly responded to your request. If you were attempting to view Billing Details, the system may be unable to return all of your charges at one time. Please use your browser's back button, and press the "Additional Cards" button to view your charges one card at a time. If the problem persists, please contact American Express Customer Services. We apologize for any inconvenience this may have caused you." Have access to lots of buttons, but all give the above msg when pressed. Website address in address bar is https://global.americanexpress.com/myca/intl/acctsumm/japa/accountSummary.do?request_type=&Face=en_AU&inav=au_myca_pc_statement_acctsum