The $5 Challenge is meant to encourage new signups at DD. Each person is permitted to play 1 free draft as well as an unlimited number of $5 Challenges (as long as the opponents are new signups).
If you believe that the rejection message was received in error, please email us at firstname.lastname@example.org
and we'd be happy to look further into the matter.
I'm sorry for any confusion and the inconvenience.