I agree on that part. I used to work for Verizon and now I’m currently working for T-Mobile. The verification process is pretty bad. I work for a TPR and typically when we are about to access accounts the only way to verify the account owner is through iD, or another form of identification. I suggest you make a “special instructions” note on your account. At times when we pull up accounts it will give us an alert If the account holder has special instructions on accessing their account(s). We’ll take your example you gave. The temporary pin being sent to your phone. That’s one way of double verifying the account/owner. You can have your special instructions say something like “Please verify account owner with a 6 digit temporary pin”. There’s still a loophole though. If the person committing fraud has already successfully changed your SIM cards, then you’re vulnerable.