no dial tone

We received a new modem from xfinity a few weeks ago. Internet is working fine. Home phone no longer has dial tone. Have restarted gateway several times. Plugged corded phone directly into gateway, still no dial tone. Tried chatting with bot - couldn't offer any more assistance. Tried calling 1-877-338-9791. They restarted our gateway AGAIN, and said I would be texted back at my cell number when restart was complete to see if it worked. Never got a text. Tried calling again, they want me to restart gateway again. Very frustrating!