I am not sure I even have voicemail anymore - I haven't at least checked for it in over a decade! :D
so I figure some organization has dumped my data to numerous call centers or something.
Yep. I have got this a lot at times. I asked to speak to managers at times, but wouldn't be put through. In the EU, there is the "right to be forgotten" and there are fines involved - but you have to be willing to push through a lot of shit.
Problem is I think a lot of these calls come from overseas call centers, so I don't think they would care about any laws.