Incorrect IP address

After recent Comcast work in the neighborhood I lost access to local channels on Sling TV, apparently because they are getting an incorrect IP address that shows me in different metropolitan area. Sling says Comcast has to fix it. I spoke with Comcast Internet Essentials; they showed me how to find my correct IP address on my laptop but did nothing to fix the problem with the wrong address being out there. How can this be fixed?