Verizon denying my trade-in credit

[enjenkolanek]

Verizon has messed up my trade-in offer so badly posting here is my only recourse.

I initiated a trade-in in Nov 24 under the current promotion to trade in any device for an iPhone 16 in any condition for free. I accepted the increased charges for a qualifying account and have since been billed. I picked up the new phone at the corporate Verizon store in Milpitas, CA in Nov 24 but did not set up the new phone on that date. I activated the new phone myself in Nov 24, and then attempted to return the old one to the Verizon store in Goleta, CA at which point I was informed I could only return at a corporate store. I then attempted to return the phone to the corporate store in Milpitas where I first picked up the new phone. They told me there was an error in the order due to incorrect IMEI and refused to take the old phone. I then called Verizon customer service and was informed by the first agent that they could only send me a shipping kit, which I never received. I next contacted another agent and was sent an electronic shipping label. I shipped the phone using this label via UPS using their recommended phone shipping box. I received notification via UPS as well as Verizon operational email that the phone was received and was being assessed. After not receiving word for several days I again contacted Verizon and was informed by the agent that they confirmed receipt of the phone and that I should wait for an update. I again waited and again contacted Verizon. This agent informed me the phone had been reviewed for battery damage; however the original offer stated that the phone could be in any condition. They insured me that the offer would be honored. All of this was withing the original 30-day timeline required by the promotion. Several days later I received an automated email that my phone had not been returned, despite my Verizon account showing receipt of the phone, and that I would not receive the promotional credit. I was subsequently charged a monthly payment for the new phone which was marked as an overdue payment. I next called Verizon again, and after an excrutiating number of questions by the agent was informed that receipt of the phone had been confirmed and that an escalation had been initiated to correct the error. Several days later I had not received a response, so I called Verizon again. Again I was asked a large number of questions by the new agent and was eventually informed that the escalation had not been completed as the new phone wasn't activated (which was done last month). They attempted to connect me to the activation department who requested my personal account PIN in order to activate my already-activated phone, at which point I refused and terminated the discussion. Science fiction couldn't write this fiasco better. What on earth can I do to escalate this to someone who will actually help?