有一张Freedom，用的很少，credit line是$20000。收到邮件会被降到$10000。值得打电话申述吗？
We periodically review customer accounts to make sure credit lines match their spending needs. During a recent review of your account and credit history, we noticed that your overall card usage with Chase and other issuers is low. Because of this, we may lower your credit limit to $10,000.00 in 50 days.
If you anticipate change in your spending needs, you can opt out of the review by giving us a call with the number on the back of your card within 50 days.