Thanks for posting to the forum! I wanted to inform that in most cases we are able to port an Xfinity Voice phone number to Xfinity Mobile. I'll need to do further research on the landline number to make sure. If you are still needing assistance with this, don't wait to reach out to me.
Click on my name ComcastChrisL, which takes you to my profile page, and from there, click on the blue 'send a message' button. In your private reply, for account access and authentication, please include your first and last name, the complete service address, the mobile number, and the last 4 digits of the pay method on file.