xfinity Assurance team

I have read that the fastest growing scam is to steal the electronic SIM card, take over the phone and get access to drain bank accounts, brokerage accounts and charge cards that are stored in the phone.  They apparently do this by simply calling Xfinity/Comcast to change the SIM card of the phone of record to a "new phone" and Xfinity will make that change.  

WHAT SECURITY DOES XFINITY HAVE TO STOP REWARDING THE THEFT OF AN E-SIM CARD ASSOCIATED WITH A USERS PHONE?  

Is there anything that I should be doing to stop Xfinity accept a change of SIM's (an extra password?) --- because sending a one time code to the old SIM doesn't work if it's been compromised.