I found my fedex receipt for when I mailed back the iphone 13 last year--how do I get my money back?

Long story short, I discovered 1 year after this happened that apple re-opened my loan with the iPhone 13 because for whatever strange reason the trade in was canceled, even though IT WAS MAILED OUT AND RECEIVED. I'm on a autopay with the citizens one apple loan, and I remember checking that the phone was indeed delivered, so I moved on and didn't think to check my email.

1 year later, 15 pro max is lost in shipment (still haven't received it btw), as I'm trying to understand what this strange 77 dollar charge on my card that I thought was the 15 (and it said 24/24 payment) the rep discovered that I have two loans I'm paying on--I'm paying the iPhone 13 pro max AND iPhone 14 pro max. TOGETHER.

The Apple rep REFUSED to give me the shipment number to ensure it indeed was delivered. I will never forget that. I could not FOR THE LIFE OF ME remember what I had done last year.

A week later I'm looking for a pic to update my profile, and I run into a series of pictures and videos of a box with the phone and seriel numbers and a fedex receipt---it was all of the iPhone 13 pro max right before I shipped it back and right after. And what do you know--I checked the tracking number and IT DELIVERED!!!!!!!

I just never received an email acknowledging it.

So now, what do I do now? How do I get my money back? I have proof! I have several pictures and videos showing it boxed up, showing me matching the serial number on the phone to the one on the box, and I even have a picture of the receipt itself! I also have the entire FedEx report, with the weight and the date of shipment, delivery, and who signed off for it.