Urgent Change MFA Email Associtated to my Comcast Email

Urgent I was just riffed (layed off) from my employer and do not have that email access. Unfortunately Comcast MFA is my Corporate Email. How/who can I open a support ticket to reset the MFA email (or add phone #) to this account. I can not add new logins to my comcast email. I need this ASAP as they will send termination information to my Comcast email.