didn't leave msg, caller ID said Five 9, which (based on internet search) is "a market-leading on-demand solution for inbound, outbound and auto-dialing call centers. All that's required are PCs and a broadband connection. Your agents can be located anywhere in the world and the Five9 system is so easy to set-up and use, your call center can be up and running in hours"
so this company seems to be enabling illegal telesales, since I am on the DO NOT CALL list.