Xfinity Mobile Rewards Problem

I recently had an offer on my rewards page to receive $300 off an Apple Watch purchase.  I redeemed the reward and got a code.  I made the purchase for the watch using the code, but realized that I had selected the wrong band for it.  I was told by Xfinity Mobile customer service that I could cancel the order, and then after 24 hours I would be able to use the code again, or they would send me a new code.  After the order was cancelled I waited 24 hours and I got a "The code you entered has been used" message when trying to apply it, the code would not work.  I called Xfinity Mobile customer service back assuming they would honor what they had told me and send me another code, or somehow get the code activated again.  I was told that I would not be able to use the code, but I could still buy the watch at full price.  I asked to speak to a supervisor and was placed on hold, after about 10 minutes the agent came back and said she was transferring me to the supervisor.  I was on hold for about another 30 minutes without the supervisor speaking to me, so I gave up and tried calling back.  The next agent told me they were escalating the issue and that a ticket had been opened.  I now have to wait to hear back from the team who handles these tickets but I have no confidence that this situation will be resolved by October 13th, which is the deadline for the offer.  I was offered a reward for being a long term xfinity and xfinity mobile customer, I was told that I could cancel the order and still use the code, OR that I would be given a new code.  I will be very disappointed if this offer is pulled out from underneath me, and my only recourse will be to explore other carriers for service.  Is it possible to get this offer honored by xfinity mobile so that I don't have to do that?  Please help a long time customer with this issue.