Figured I'd give an update on this issue.
Verizon called a week ago (10/18) and said that they would fix the CPC issue and was confirming of the exact problem.
Verizon called last Thur (10/25). They said that the pots card at CO had been swapped for on open loop disconnect card and wanted to know if my problem was fixed. Since the tech called my landline port I had him hang up while I left my phone off hook. I saw no messages in syslog for CPC which indicated they weren't sending a disconnect signal to the OBI212. I also changed the OBI212 CPCTimeThreshold a few times, retested and still no CPC signal in syslog.
The Verizon tech called back a little later to confirm the issue was fixed which it was NOT. I suggested that if in fact they swapped the pots card to an open loop disconnect card, maybe they should program in the CPC signal. The tech said he would keep working on the issue.
I'm not going to hold my breath on Verizon getting the problem fixed, so in the meantime I decided to find another solution to the problem.
I added asterisk-16 to my Linux Server and setup a voicemail extension. I then configured the open sp3 SIP port on the OBI212 to connect to my asterisk SIP server.
Now instead of forwarding my landline to callcentric voicemail after 5 rings it is now being forwarded to the asterisk voicemail. Asterisk voicemail is now telling the OBI212 to hangup the landline when the call is done.
So far this is working quite well for the landline, but there are a few small issues forwarding GV calls to the asterisk server, my guess it's due to Verizons crappy DSL.
Now I just need to figure out how to get my OBI202 to dial the asterisk servers voicemail to check messages. Unfortunately the OBI202s (SPx) ports are all used.