Charitable Phone Calls

While we can all appreciate the fine work done by charities, the following has to stop. You get solicitation phone calls from them asking you to donate. They ask you to donate a certain sum or they will say how much they want. If you tell them that you will donate providing you get the written information in the mail, they go on and on and repeat themselves. One doesn't want to be rude but one is going to hang up the phone.
How about these charities that call you and don't answer when you pick up. You hear noise in the background. They are calling to see when you're at home so they can call again. This is absolutely absurd.