Why not just say: me and my friend, we wanted to do an online business, it seems the bonus money offer was way too much, someone won big, we couldn't afford to pay so now I am saving whatever is left to be saved from our reputation. You are not the only one who tried to create a business and failed, rest assure, without failure you can't prospère. I mean of course you had to pay the users with your own money, you were part of the project, part of the team. Do you want us to make a pool to reimburse on your mistake?
Acting like a victim is lame.