I do not know how to add you back to the tournament. I will ask a Battlefy employee to see if there is anything we can do to resolve this situation. I was culling through activity problems / people who wanted to drop last round and took that message to include you as a part of the latter category. I'm really sorry that I misinterpreted.
http://www.smogon.com/forums/threads/official-smogon-vgc-17-tournament-round-3-pairings-see-post-410-extension-deadline-2-8.3594153/page-16#post-7220762
In it, it was stated that you forfeited. I was unable to find any posts from you in that thread or any messages on your VM wall, so I took it as if you forfeited the match and dropped the tour out of request.