suppling buttons for a club/organization I don't believe in...

It's exactly like the title says. I agreed to do buttons for a group of people, without asking what they were about. Why would I? Well, once I got the check in the mail, I got suspicious as to what it is they do. I did some sluething and it seems to me, they are a group of people that hunt. I have yet to make these buttons. And I'm working up the courage to say something. Because I can't morally do these for them.

A friend, however, suggested I make the buttons, and donate the money to a charity in their name, and mail them the receipt.

Suggestions?