Being accepted then rejected to an academic conference I submitted an abstract and received notification of acceptance to present at a conference.  The notification of acceptance asked for a short bio.  I provided the bio and was asked to provide more info in my bio relating to my academic and professional background. I provided the requested info touching on my experience in multiple disciplines in academia and industry.  I received notification today (10 days after receiving acceptance) that my submission has now been rejected.  They cited concern over the depth and breadth of the topic.

This hasn't happened with the many conferences I have submitted to.  I am not sure what to do handle this situation?  I have already devoted time and efforts to securing funding and completing the necessary studies to present.  Should I make attempts to rectify the situation and figure out why this was retroactively rejected?  Is this normal behavior for an academic conference?  Should I attempt to find out what happened in their review process?  What I can do to rectify the situation of having this submission retroactively rejected?
I'm inclined to think the simplest answer is human error. Someone overbooked a set time slot and your acceptance was taken back. 
You'd be hard-pressed to get anyone to admit that, though. ;)