xfinity mobile and internet security failure

2 weekends ago I experienced a breach of my Xfinity mobile and e-mail accounts.  Xfinity allowed another individual to add a line to my mobile account WITHOUT MY AUTHORITY.  With that mobile account, the individual was able to access my Xfinity e-mail account and used that access to break into several of my personal accounts, including at least 1 bank account and my Paypal account.  Within my email account, the unauthorized individual adding an email forwarding address in order to intercept my requests to reset my passwords.

I managed to get back control of my accounts after many days of telephone calls and a visit to my bank.  Xfinity's response has been disappointing.  (1) No explanation of how the individual was able to add a phone line to my account and access my e-mail; and (2) extreme difficulty reaching Xfinity's customer support regarding the matter, including sending me to a fraud department number that resulted in a wait time of 45 minutes before I was advised that the number I called was NOT the fraud department.  My advice to other potential Xfinity customers is to avoid Xfinity mobile service as it seem their account security is non-existent.  Further, do not trust your xfinity email account for anything of importance.