May I come with a suggestion?
How about you live stream the picking of the winner? I would assume you could hide the account name, but only show the character name that has been picked. It's all fine you do it your way, but keeping it all hidden away, makes it less trustworthy. The particular prize is a big one, and people will of cause easily get upset, if they do not win, as many probably hope to be the winner. That is why, if you stream the picking of a winner in some way, or make a small video of the draw, you will gain from trust, instead of having to battle people like those in this thread, that claims the server has scammed them, in some sort of way.