Don't know how this can help by just saying i got the same call, but I got the same call... my vm was also picked up after the message had already started. Mine was not cut off as late as previous report so if it helps here is more of the vm:
"... and a non bailable warrant has been issued against you by the Internal Revenue Service... So before we move forward with the lawsuit, call us back at 509-592-4766. I repeat the number is 509-592-4766. Should I call back and find out more?