Who to speak to about @COMCAST.net to @Yahoo.com email disasters?

Hello. My apology for the alarming word "disasters" but for the past hour I have been trying to contact someone at Comcast about the @Comcast.net to @Yahoo.com email migration.  Your own site says to contact you before migration and Yahoo after migration. But there is no way to contact Comcast/Xfinity about this migration. And we all know Yahoo does not talk to any customers unless the customer pays them to speak with them. I realize that Yahoo, Google with Gmail, AOL, and other Free Email companies should have never ever offered free anything. They should have been charging from day 1. Now they are going to [Edited: "Language"] the world while crying the users are stupid, they have no idea what they are doing, etc...Neither do the employees at those companies. WHO CAN I SPEAK WITH ABOUT THIS COMCAST TO YAHOO MIGRATION?  Because stuff ain't working on Yahoo's side and we all knew that would happen. Thank you.