Added lines and bought phones at Costco. Wife wants to return new phone for different one. Will this screw up all rebates/trade in credit?

Ported in two new lines at Costco and added two iPhone 16s and declared two phones for trade in. My wife doesn't love her iPhone (she came from a Pixel) and wants to go back to Android. Will this screw up the various rebates and trade in credit?

Also since it was Costco, the phones had to be shipped. Does the 14 return window start on day of shipment? day of receipt? day of activation?