Trade In Confusion

I'm having trouble initiating a Trade In, and I would love any advice-


I received the $699 offer to trade in an Iphone 4 or newer, for an Iphone 12. I called Verizon, and got connected to a sales rep. The sales rep confirmed that trading in an Iphone 4 or newer in good condition, plus upgrading to an Unlimited premium plan, would allow for the $699 credit. I finalized the transaction with the sales rep, who told me that, after I receive the phone in the mail, I would go online to initiate the process to trade in my phone. I received the Iphone 12 in the mail, with no packing materials or instructions with regards to trading in my iphone 4s. I went online to the Verizon Trade In page, and entered the information to have my Iphone 4 sent in. I was informed that my phone has no trade in value, and I would not be able to send it in...

Am I missing something? Did the sales rep give me wrong information. Any advice would be greatly appreciated.