I am not sure if the people running the challenge come to these forums much, but have you completed your registration? Do you have a contact with the competition organizers that might be a faster way to get an response.
A quick check on the website looks like Registration is still open.. in order to not give early registrants an upper hand, they may be holding off on the approvals until all teams are registered and the kick off to the competition begins.
These are just guesses of course, I don't know a lot about the competition myself.
Good Luck though!