Backordered iPhone XR - can I cancel?

I ordered an upgrade to a black iPhone XR on Nov 25. At the time, the estimated availability of the device was Dec. 4. It is a gift for my daughter for Christmas and I figured I would be ok. The white option was out of stock. Now, on the website, white is in stock and black shows availability of 12/16. I am worried it won’t arrive in time. My billing/status order says estimated Dec 31, 1969 🙄, so no idea what that is about. Is there any way to change to the white phone instead or cancel the backordered phone and reorder the other color? Has anyone else run into this problem. I spoke with 2 different level 2 customer service reps and 1 said they could request a cancellation but the other said they could not.