This is an automated calling system with a computerized voice. Just do something like ask if he is a robot and the system will respond with a canned answer such as, "Ok then, well we are calling to ..." and wait for your next response. Don't get upset over the phone because you are talking to a computer.
After several calls a day, husband finally picked up and caller knew my husband's name. Very pushy guy who insisted on us pledging an amount of money before they would mail anything to us. We never give money over the phone - we ask for information to be mailed to us, then we check the charity via the Charity Navigator website. So finally my husband said to put us down for a pledge of 0 and please send the pledge card. The caller hung up.