iPhone trade in accepted by Apple but I had bought the phone from Verizon

I traded in my iPhone 14 Plus to Apple for the iPhone 15 Pro Max. Apple credited me $470 for the 14. Nowhere did I see any proviso stating that a currently financed phone could not be traded in. Apple accepted the trade refunded/credited me $470 but Apple didn’t own the phone, Verizon did. 

Now, Verizon says Apple shouldn’t have accepted the iPhone 14 plus trade in because I was still paying Verizon off. 😳 I did get a credit which Apple now says I owe to Verizon.

Anyone??

[Re-Titled by Moderator]