Same thing happened to me.
I found this information from MileageAddict's previous post:
MyPoints.com
565 Commercial Street, 4th Floor
San Francisco, CA 94111-3031
Telephone: (415) 676-3700
Fax: (415) 676-3720
www.flyertalk.com/forum/Forum1/HTML/001503.html
And steve100 posted this in another thread:
1-888-262-4528 or 1-888-333-6260
Hope this helps.