Thank you everyone for your help today. This is truly a wonderful board full of kind, helpful people.
I spoke to DH tonight when he got home from work. He had an interesting perspective. He believes Target might actually think there is fraudulent activity on my card. I didn't use it very much at all prior to my churning which started a couple weeks ago. He thinks they may truly want to verify that someone else doesn't have my card since my spending pattern changed so drastically. We talked about it and will fax them the documentation they want on Monday. Hopefully that will clear things up, but with Target, who knows!
I'll keep you all posted. I sure hope this doesn't happen to anyone else.