STB not delivered

I was suppsoed to receive a third STBox on February 28, 2018 that I ordered online the night before (2/27). I received a message that stated Verizon's records showed that my STB had been delivered on 2/28/18.  Ever since then, now 6/19/18, I have struggled to get this problem corrected.  My billing is now for 4 STB's since they sent me a replacement for the undelivered STB, and that box was inoperative. I returned that one and received yet another one that finally worked.  However, the records are still indicatimg that I have 4 STB's. Can some one show me how to reach beyond the CHAT folks and the Customer Srevice phone people to get this resolved?  I have spent hours trying to sort this out.  Each time I am promised by reps that it will be corrected in 7-10 business days.  I've been promised something over 7 times.  I have copies of the chat sessions to prove it. Is there a mailing address that I can send a letter to that might begin action on this matter. I know if I don't straighten this out, Verizon will charge me for the loss of an STB which I never received.  I contacted UPS, who I was told was the delivery carrier, and they searched their records for anything delivered to my address from Feb 1 through April 1 of 2018. Nothing from Verizon was ever delivered.  I would appreciate anyone's insight here.

Re: STB not delivered

Hi Walf1947,

Your issue has been escalated to a Verizon agent. Please check your Private Message Inbox for a message from Verizon_Support. You can find your Inbox by clicking on your username at the top right corner of this page. Please direct all correspondence concerning your issue to the agents who will be assisting you privately.