Xfinity ordered me the wrong phone - now won't get me the right one

I went to Xfinity 2 days ago...wanted a new iPhone SE in RED. they did not have one in stock so the agent ordered me one. Today it was delivered but the phone was WHITE. I immediately went to the Xfinity store and asked to exchange it for the one they were supposed to have ordered -- no deal. Said I had to go to the Apple store to return it under the warrantee program. Drove to the Apple store & they said they would NOT exchange it ( it is unopened & in the original box). Went back to Xfinity & the manager gave me some paperwork to go to Apple to exchange it under the warranty. Went to a 2nd Apple store and was told, again, they would not exchange it & even if there was something wrong with it, they could only exchange it for the same color under warranty. Went back to Xfinity and their response was "There's nothing we can do. It's your problem." THEIR EMPLOYEE MADE THE ERROR AND THEY SHOULD CORRECT THIS!!! What's the deal?