I've received this call from 4 different numbers over the past 2 weeks. They show up on my grandcentral.com account as coming from the United Kingdom, with a +44 prefix. Here are the numbers (I'm posting this comment for each number, on this site, for cross referencing):
When I pick up, the recording is in mid-sentence, and says something like "This is your final notice for an interest rate reduction. Press 1 to speak to a live operator." When I pressed 1, I got put on hold for over 6 minutes (all the while planning to place THEM on hold as soon as they picked up), then finally the hold music stopped and the call ended quietly. Nobody ever answered.