Who's going to do that? It won't be anyone on here since you can do that better than we can. This site doesn't offer call blocking, or placing individual's numbers on any no call lists.
I work for a national federally registered non-profit organization. Robo- dialers and pressuring people for donations is NOT the way to raise funds or awareness of your cause! Mail or the chatity's official web site are the best way to donate. I got a call from them today. No message was left.
Now days, with all the telemarket scammers using spoofed (false) numbers and names, you can never be sure who is really calling. It's best to, as you say, to give directly to a charity you trust. Using a credit card costs the charity a percentage, and giving to a hired telemarketer costs the charity much more yet. After studying the charity thoroughly, the best thing to do is write a check.