At first I thought it was the Better Business Bureau which has called for years trying to get me to sign up. Then I saw the area could an assumed it was a scammer. No voicemail. The BBB always leaves voicemail so based on that and the other comments this is a scammer spoofing a name that is likely to get you to pickup.
I used *67 to call back. There's a well spoken generic message that gives options for speaking to a rep or getting on their DNC list. No company name is mentioned. Impressive scammer.
Many credit card companies are traditionally based in delaware. Perhaps a credit card company. Or perhaps some douche in Bangladesh with a spoofer. Or maybe Uncle Joe is lonely now.