Hmmm. So they are saying it was a fake site by the sounds.
Damn this is a tough situation. Very hard to know if this is some sort of scam by them or if you really were tricked. You'd think that they should know immediately without an investigation though, so it does smell suspicious.
Please fill in a complaint form and maybe SBR can help find out more for you:
http://www.sportsbookreview.com/sportsbook-complaint/
Mention if the 100k was won in the casino or sportsbook too. As we may be able to approach that supplier to confirm if their story is true.