unknown numbers on bill

Why do numbers show on my bill as 999-999-9999 for outgoing texts and they do not show in the Text online area of my account? These are not recent texts they are months old. I understand sometimes you will get texts from 000-000-0*** because you requested a reset code for something or its an automated dialer for pharmacies etc. I also understand that you can receive 999-999-9999 text and calls when people block thier number, what I do not understand is how they are being sent that way and why they do not show in the Text online or the phone (which can be erased)

Re: unknown numbers on bill
Customer Service Rep

DK73, I can definitely understand your concern when it comes to the text messages showing up properly on your bill. I want to make sure we get to the bottom of this, so this doesn't continue to be an ongoing issue. To clarify, is this showing up for regular text messages you are receiving from friends and family? ChetonJ_VZW