Logging in to old xfinity email

[0094]

I changed my xfinity username, which in turn changed my email address. Now email being sent to my old email address is not being delivered to me.  I have added the old email address back as another user on my account and the invite is pending.  I am unable to accept the invite because xfinity no longer recognizes it as a username and I have no way to log in to that email address to accept it.  Is there any way to solve this?  I am missing so many things that are being sent to that email address with no way to retrieve them.  

[BruceW]

If an employee doesn't reply to your message here, Comcast Security Assurance might be able to restore the ID for you. You can reach them at 1-888-565-4329 (from https://internetsecurity.xfinity.com/help/report-abuse/). Note that this is NOT one of the general customer service numbers.

The first-line reps there are sometimes not very helpful, so you may need to be persistent and keep at them until you get a satisfactory answer.