Xfinity Voice not working

I recently upgraded my equipment to a Voice and Data Modem TECHNICOLOR CGM4331COMSerial #: 80DAC2DD12F5. The internet works fine. Voice does not. Reset the unit multiple times. Tried both ports. Tried different RJ11 connection. Still no dial tone. Can't figure out how to talk to live agent after trying the online assistant, the phone app, and reading all the troubleshooting articles on line. How can I get help to get my phone service back?