Someone stole very important things from me?

I had this friend ( i'm 14 ) who turned out to be a criminal. One day I found that my iphone was missing while the door was open because my brother left it open and i never found it. Then a week later I let this person inside (i didn't know he stole it yet) and we played on my xbox he was playing with these things called zenmagnets which are like 125$ then he left i couldnt find them so i went outside to see if he could help me look for it he agreed and we looked through the whole house and couldnt find it then he said he knows someone who has zenmagnets and that they would lend it to me ( he didn't know the price of zenmagnets so he came up with that stupid lie)
i said okay so my little brother went with him to get it and he said he went into a bush a got the zenmagnets from there instead from his friend. So i got them back and i grew suspicious of him. Then oneday he came over again and this time without knocking came into my house to ask if i could come out side. I said no and to get out my house and he left. When my mom came back she noticed that my gold braclet that i had since i was a baby was missing (it wasn't a big deal to her but it was to me because it had a lo of memories.
So a month and a half later my mom went to give her old camera to a pawnshop so she could buy a new one (the expensive kind) and I saw my gold braclet with my name on it in the pawn shop we couldnt get it back of course so my mom went to talk with his and when she came back it turned out his mother had the same i phone and case I had with the same scratch that i had on the back of my iphone! So she asked the mother and said her son found it at school. My mom then asked for it back then the mother was yelling at my mom saying it was hers and that she couldnt take it.

Sorry for the terrible punctuation and spelling but what do you think we called the cops and they said there's nothing that they could do about it unless they wanted to go to court (i didn't think this was true) but what should me and my mom do?
overall $775 was stolen iphone 3gs $275 gold braclet $500

I would have called the police WHILE TI WAS AT the pawnshop and told them that it was mine and it was stolen.

You should phone the police
a pawn shop has to take reasonable measure to ensure ownership of any item they buy or issue a loan
your mother will have photos of you wearing it, so you can prove its yours and the police will seize it
and after a court case you will get it back
tell them about the phone and the should be able to retrieve it also