Amex接了retention offer并且完成任务拿到奖励了，可以升级吗？之前的奖励会被clawback吗？
补一个当初的terms: 只提及了cancel/downgrade， 没有提upgrade:
If you have a history of cancelling or downgrading American Express Card accounts within your first year and you cancel or downgrade your Card account within your first year after this call, we may not credit, we may freeze, or we may take away the statement credit from your account.
If we determine that you have engaged in abuse, misuse, or gaming in connection with this offer in any way or that you intend to do so, including if you return purchases you made to meet the threshold amount we may not credit, we may freeze, or we may take away the statement credit from your account. We may also cancel any accounts you have with us.