A security deposit is supposed to be returned within one year of ontime payments.
you are late even once it starts over again. Your attorney generals office in your state is the place to go to have them go after Verizon.
verizon makes it easy to get a customer but hard to have one cancel. Even if you get a phone rep, many times they don’t process your request. In this case your states Public Utilities Commission or Public Service Commission is a place to file a complaint.