Telemarketing scams are the new email spams. Once you get a call you will receive many many more. Criminals are desperate for your hard earned cash. All they want is your credit/debit card information. NEVER EVER GIVE OUT PERSONAL INFORMATION OVER THE PHONE!!! NEVER.
If you want to give, give to reputable organizations. Give locally or to charities that are reputable. Beware folks and report the calls. Warn others.