Trade In Issue

I recently upgraded my phone on 10/4 and returned my iPhone XR. On that same day I upgraded my daughters phone to a 13 and it came in on the 22nd of October and the same day I sent back her iPhone XR 64 gb.  On the 22nd my moms phone came in and she didn’t want it so she returned it for the pro max without the 13 being opening. On this day somehow the iPhone 7 plus got switched on my daughters account instead of my moms. Now we returned the XR and received no full credit for my daughters phone. My mom still has her 7plus because she’s not trading it in at all. She is buy her pro max out of pocket. So why did things get changed? And why am I not receiving full credit? That was the point of upgrading my daughters phone because it was basically free when trading it in. Highly upset. Also tracking number says it was returned but it won’t go on the account because it’s looking for the  7 plus which will never be traded in. Please correct this please!!!