WGT doesn't allow restarts to play in any credit involved comps, before they reach their previous tier, therefore, a restart hack playing the showdown is illegitimate... Unfortunately, this is not really being policed...
Agreed. I think that WGT's policing only starts when somebody in the Community reports a player for a suspected violation. It's not an automated thing.
So, to that end... Lesley, I'd suggest you report the Level 17 Hack you mentioned to WGT. Not a perfect solution, I know, but unfortunately it's all we have right now.