Recieved letter about an old verizon fios account

I am a former Verizon FIOS customer in florida, my account was taken over by frontier a couple of years ago. I just recieved a letter from Verizon addressed to me stating that the email address on my account was changed via the call center. The partial account number in the letter matches my old Verizon account number. I have not been able to find out any information via the phone becuase I do not have an active acount. Did someone impersonate me to Verizon? Who can I talk to?

Re: Recieved letter about an old verizon fios account

Hi Revenant,

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.