Landline Not Receiving Incoming Calls

Started my Xfinity home internet and landline service a few days ago; the internet has been working fine, but the landline only works for outgoing calls, it does not receive incoming calls.  When it was setup initially a few days ago, I very specifically asked the technician if all I had to do was plug in the existing landline phone, and he said yes, the service was already active so I just needed to plug in the phone.  He showed me which slot to plug in the phone line (it's obvious, but I still marked it to be sure), so I am in the correct jack, and the phone worked at the old home, so it should work at the new one.  I have tried reseting the router myself, plugging and unplugging the landline, switching outlets for it on the router, etc, all without success.  I have also attempted to get help from customer service via phone, but only get an automated system.  The automated system reset the router, but this did not fix the issue.  Please help!