At the suggestion of a member, here is the general contact info for Amtrak Guest Rewards.
5:00 AM to Midnight, 7 days a week
Amtrak Guest Rewards
PO Box 14368
Philadelphia, PA 19115
Fax 1: 215-856-7708
Fax 2: 951-789-7898
Note: Select, Select Plus and Select Executive AGR members have a different phone number to call for priority service. Check the back of your membership card for that number.