Return Phone Issues

I purchased an iPhone 17 on July 4th because I lost my iPhone 15.

I ended up finding my phone a few days later, and went in store to return the new phone on July 17th. I was told to come back the next day instead to meet with the store manager so he could waive the return fees. 

The store manager was able to transfer my number back to my old phone the next day, but he told me the system needed 24hrs before the return could be processed because the iPhone 17 was showing up as "undefined" after the transfer. I noted to him that the following day (7/19) would be outside the 14 day return window, and he said it would be fine.

I came back the next day and the employees submitted several support tickets but were not able to process the return, and after calling customer service I've been told it's specifically because it's outside the 14 day return window (even though they and I have explained the situation). I'm now also being told that the store manager added a second phone line to my account, unbeknownst to me. 

According to the employees, the store manager has submitted another ticket and is escalating this to corporate, but this is taking way too long to resolve with minimal/false information being relayed to me, and I'm about to be charged the monthly payment. I'm asking directly for escalated assistance.