Scammers. The criminals are looking for victims to steal from. All they want is your identities and credit card information.
NEVER EVER PROVIDE PERSONAL INFORMATION OVER THE PHONE. Especially to robo callers and "Unknown Name." If a legitimate business or bill collectors wanted to contact you, trust me, they will mail you and use proper caller ID.
Beware folks. Telemarketing scams are on the rise. Be smart.