i would do 2 things:

1. Contact support, if your number is now in the posession of VoIPo and the port is complete in there system cancel out the service. If finishing of port is in process (is possible) keep your service for now.

2. Call Comcast, ask if the service is to replace equipment on site, or more specifics. They may simply be swapping out your equipment in your home to something that doesnt support phone to cover part of there costs.