I read the first post and there actually is a March of Dimes.. It sounded familiar so I googled it..
http://www.marchofdimes.com/ who ever called you though was probably the scammer ripping of the charity name.. I would e-mail the people at this website to make sure its legit.. Even just to find out whats going on and if they would really auction off a puppy.. Maybe you'll help catch a scammer.