Secondary E-mail Accounts

I am no longer a Comcast account holder, but have kept my Comcast e-mail addresses (as I was told that this would never be an issue).  I am now unable to access 3 of my secondary accounts.  As recommended, I periodically attempted to log in to these accounts via a browser.  At some point a password change was required.  However, it would not let me perform the change unless I was logged on via my "Home Wi-Fi" network, which is non-existent.  Now, I am locked out of e-mail accounts that are essential to me.   I have been to the xfinity store.  I have called the number that was given to me.  I have received no satisfactory solution to the problem.  For the record, I have been doing everything that Comcast told me to do, but there is no way around the security process you have put in place.  Please tell me how to turn these accounts back on so I can at least set up forwarding to another address.