Two clicks
Click 1 = ASK AMA tab on top right of main page
Click 2 = To contact an AMA staff person directly you may use the staff directory.
clicking on the "staff Directory" link gets you to this page:
http://www.modelaircraft.org/members...n/hqstaff.aspx
That page has several listings, including the AMA Membership Director:
[email protected]
And 3 weeks is not out of line to receive your printed card. You were officially a member the moment your application and payment were received, but sometimes getting the card can take some time since they are printed in batches.