Judging by your location, I'm going to assume your talking about the Ontario Reptile and Aquatics Expo in Mississauga, correct? This is the expo I also go to. If you don't mind could you tell me who your bought your snake from? Just so I know to stay away from them in the future.
Why would you avoid the breeder? They're reputable, not to mention she probably got the mites from the log I bought or just from the other snakes at the show. She didn't have them upon purchase.