Exchanging phone within 14 day period

I recently upgraded to a brand new phone at an Xfinity store near me.  The phone just isn't what I want at this time so I went back to store to exchange.  They told me they don't have any other phones in stock.  I visit 4 other Xfinity stores that are closest to me, and I am told the same thing.  A few days later I visit the store I originally upgraded at the following.  Tell them I am interested in a new phone, they have some, explain that I am looking to exchange because I am in within the 14 day period. 

After employees say they are checking the policy, they say I may exchange.  So after about 20 minutes or so they have to contact chat.  The person who is helping me (I have no hard feelings towards the associate that was assisting me that day, he really seemed like he wanted to help) tells me he is having an issue because my trade in credit is causing issues.  I did not trade in any phone, and I have not traded in any phone ever.  I am also told the watch line my account may be causing an issue.  This is odd because this didn't cause any problems a few days prior when I upgraded.  The watch was not connected to the line that I upgraded.  After about an hour I am told this cannot be resolved today and that it should be on Monday (I went in on Friday).  They take my phone number and tell me they will call me if it is ready sooner.  I tell them I am worried that when I return that they will not have the phone in stock that I was going to exchange for.  I am told they will hold it for me.  I am also concerned that when I return tomorrow that the issue will not be resolved and I will be past the 14 day buyer's remorse period when it finally is resolved. 

They guarantee a 14 day buyer's remorse period for exchanges, but the phones are never in stock at the retail stores.  They say they cannot order one and I am told this has to be done in store, and cannot be resolved online.  This situation is extremely frustrating.  I have been with Xfinity mobile since the very beginning, right at it's launch.  I have been using Xfinity Internet and other home services for as long as I can remember.  I have never complained, I have never tried to exchange anything in the past.   I just want to make an exchange, and based on the buyer's remorse policy I am entitled to do so. 

Has anyone had an issue like this in the past?  Online chat has been zero help.  They just try to sell me another line/phone.   I don't get why it has to be this difficult to make a simple exchange.  Based on the experience I have had this past week, driving hundreds of miles to different stores.  XFi Mobile customers have no other choice because you cannot simply call a store and ask if they have stock, and employees at stores are unable to tell you if another store has stock.  If you upgraded in store and want to make any sort of exchange you have to drive around and just hope the next store has some sort of stock.  It feels like that I am just going to be out of luck and stuck with a device that I do not want.