Hang-up calls, probably "Cardholder Services," who call me all the time in spite of repeated requests to remove my number., or some other scammer or phisher. Reverse look-up shows Telcove of Vermont in s. Burlington. Phoning 242-4334 yeilds, "You have reached the campaign voicemail. Please leave a message." Of course, campaign calls are exempted from the do not call registry, so this obviously is a scam.