How can I report a missing iPhone and resolve insurance issues with Apple?

I have a ? This happened a couple months ago ago and we don’t know what to do my mom gave me a I phone she is paying for still on her Apple Card I went out of town she disconnected it so that I can put on my account so at that point she factory reset the phone but I couldn’t connect it at that moment cause I had to go in a store so I took the phone with as planning to connect it when I went out of town I was busy I ended up not connecting it right away as I returned home and realized the phone was missing and I couldn’t connect it as we call to try to report it they told us that we are lying about the phone being missy when it has not been turned on they’re seeng on their side but the phone has no where about and they won’t don’t thing about it and we still have to pay insurance on the phone when we do have it and pay for that phone as they flagged our other phone and the new phone i bought cause that on went missing what can i do about this and where can i go about this situation someone please advise?

[Re-Titled by Moderator]

Original Title: Help please??