I called the AA RTW desk to make a change to the date of my ex-CAI AONE3, they said it would require reissue. Although the fare has not changed since I issued the ticket, the EGP:USD exchange rate has decreased significantly (6.22:1$ now is 5.8:1$). If I reissue, will I get charged at the new exchange rate?. Or if I refund the ticket, will I get USD back at the new rate?