I understand where you're coming from. If someone does want to donate to a charity, make sure you do it as anonymously as possible! Never provide any kind of legitimate contact information or they will hound you like a swarm of mosquitoes.
I ran into this problem with Habitat for Humanity. Before Caller ID and when answering machines recorded on tape, a caller would call every day at about the same time and hang up at a point where my answering machine would run the tape to the end with nothing on it, preventing any legitimate callers from leaving a message. One day I was home from work early and at the time of the mystery calls the phone rang - it was Habitat for Humanity who I had donated to just a couple of weeks earlier. I made it clear that their calls were unwelcome, and lo and behold the "mystery calls" stopped.
NEVER give any charity your contact information! They will hound you day in and day out!
They called during the day and I answered. The woman said they were from the Cancer Society and asked me to (more like tolds me) to mail out fifteen information packages to my neighbors in October(Breast Cancer Awareness month)and I would have to pay the postage. I agreed (our family has been plagued by cancer and I am a donator) and she confirmed that I would pay the postage then ended the call. I found it odd that she did not confirm my address. They called back two days later on a Sunday evening my husband answered and requested they take us off the call list. They requested to talk to me several times but he refused but they have not called again.
Just the way they handled things made me question the authenticity of the call.
three calls this week alone after one call two weeks ago. WHO ARE THESE PEOPLE?? as others have suggested, we do not answer the phone so as to not give them any authentication of our number. i hope the person who said they eventually move on is correct!!!