Xfinity refused to send me mailing label to return a trade-in, and won't give me credit

I have spent over four hours on chat with multiple representatives and the issue is not resolved.

I purchase two new iPhone 18 (one Pro, one ProMax) and was supposed to get credit for a trade-in.  The Pro phone came, I activated it, and was sent a mailing label to return my Iphone Mini.  

Same transaction.  I initially had a TERRIBLE experience because I had to go through additional security verification hoops, where *nothing* worked properly.  After spending multiple hours, we finally got that resolved and the iPhone 18 Pro Max was shipped out.  I received it, activated it, and am using it.  However, no mailing label.  The two-hour online chat today boiled down to this:  the Pro Max did not have the trade-in listed in the original order (error on Xfinity's part), so no mailing label can be generated.  Xfinity's solution?  Send the Pro Max back for a refund, reorder with the trade-in, and start the process all over again.  THIS IS INSANITY.

I got hold of someone who said they were in the retention department (don't believe that - sounded like a normal international call center in the background) who kept sending me texts to verify identity (which never came through) and an email to verify identity (which had a link that wouldn't work).  I finally hung up since I was getting nowhere and could hear the other representatives conversations better than my own.

I have been an Xfinity customer for *over thirty years*, and if I don't get some resolution that doesn't require ME to do all the work, I will be sending back both phones and canceling my Xfinity internet, cable, and mobile service.  

Someone with Xfinity needs to contact me.  Please don't suggest Direct Message, because that appears to go to a comcast.net email that I have NEVER used and have no access to.