Sounds like you want to send all 12 numbers to 1 phone, ring and if not answered route to their own voicemail.
To do this you could set up 12 x ported extensions, the extensions would be the DNIS of the toll free number.
Create a coverage path that routes point 1 to the extension you want to ring and have answered, then point 2 to be voicemail and assign it to all of the x ported stations.
If the extension in point 1 doesn't answer after ringing it will route to voicemail for the individual number.
- Stinney
Quoting only proves you know how to cut and paste.