Is this post-secondary but pre-interview? If it is, what I suspect really happened is that you got rejected based on your AMCAS application. Vanderbilt bases interview invitations based solely on the AMCAS application, and the secondary application does not need to be filled out until you receive an interview. It sounds like you filled out the secondary and made a donation to Vanderbilt, for no reason.
Nevertheless, sorry Shamthis. It still hurts.