Caller ID says, "Derby CT"--so it looked like a legit no.-- a person from 1-800-Zero Debt said they mailed some information on debt mediation and were following up. Put on blocked numbers list.
Follow up: when I tried to block the number automatically, another local number came up instead of theirs. Very strange. So I blocked the number manually.
They call multiple times a day. No answer, no voicemail. When I try calling back, it says calls may be recorded please hold for next available customer representative. Then it goes quiet... then busy signal. SO ANNOYING.