I received a call from that number and let it go to voice mail. It left an automated message saying that while my account is fine I should call them for low interest rates; since they did not mention who "they" is I know it's fake. Therefore, it is some sort of automated spam sales pitch. Interestingly, Google Voice Mail recognized it as spam because when I went into my mail to see the transcript of the message, the message was not in my In Box where a voice mail message would normally be but in my Spam folder.
I picked up to hear a pre-recorded message, press 1 to reduce rate to 6.4%. NO BANK will ever call you urgently requesting that you reduce the rate. That's how they make their money. Definite scam.
For those of you that get these calls on a cell phone, I have a tip that I'd like to pass along. Works better than the DNC registry.
Once I determine a number to be a scam (or unwanted) I save the phone number in my contact list, and set the ringer tone to "No Ringtone". So, the next time they call, I don't even know it until the next time I look at the phone. I see a "missed call from scam." And just move along without missing a beat. No disruption or anything.