Who is the cell provider/carrier, drop it off at one of their locations. The carrier can notify you that they have received it and sometime will mail it to you if you cannot get to their store.
I found a phone once and that was exactly what we did. We met at the mall, I handed him his phone, he said thank you and that was it.
You should ask them to hand it in at a well known store, then you can collect from there. That way you don't need to have contact with them. I expect they are hoping for a reward.
Why don't your parents or another adult accompany you there ? They should... seriously...
No! they could try to assassinate you as part of a government plot to destroy everyone who ever had contact with the phone so that they can use it as part of another conspiracy to bring down the Canadian government and make it a state of the US!!
Ok, joking over: Maybe the person who found it was going to be in that mall that day anyway and thought he would kill 2 birds with 1 stone, do some shopping and give back the phone. It doesn't sound that odd to me. It IS a crowded mall, its not like its a back alley.
No, you should do it in some remote woods at night
In a busy mall, sure. Nowhere else.