According to US law, telemarketers must allow the callee to ask to be put on a “do-not-call-list”. But what if they leave the message on an answering machine? Is that in violation of the law since they callee doesn’t have an opportunity to ask to be put on the DNCL? Or is leaving a number where the callee can call back and ask for the DNCL enough?
I would guess it’s not in violation because the callee doesn’t have an opportunity to ask to be put on the DNCL. If your answering machine specifically instructed everyone who called you to put you on the DNLC, they would have to comply.
Information on the FCC’s Telephone Consumer Protection Act can be found here.
My guess is that they would not be in violation for the initial call, if, like you said, they left a number where they could be reached. However, if they left you a message on your answering machine AFTER you asked to be placed on their DNC list, it sounds like you’d have some great evidence to go after them.