lost&found???

[littleowl]

Hello sorry I tried to find where to ask this but couldn't see any posts related with a similar thing.
I used to work for royal mail in a mail centre (I'm on a career brake at the moment) and I had seen that sometimes people throw things (in the red mailposts that are on the street) that aren't mail. Some of the things that I have seen where lost phones or wallets.
I lost my phone in Manchester some weeks ago and I was wondering if maybe the person who found it could have dropped it in a mailbox and maybe Royal mail have it in a lost and found room.

I know the police doesn't have it. I contacted them. The phone had a lock pattern in the screen, this person was unable to see my contact list but they replied to my husband's missed calls by clicking on the screen to "call back missed call". I think they were trying to reach me to return it. My husband couldn't answer when they called because he was driving and the phone was in silence mode. I only realised they tried to call me when I saw in my bill, but by then I already had cancelled the sim.
I think this person wouldn't go to the police to leave it there so the only other behaviour I think they could have would be maybe to throw it in a mailbox and forget about it.
My question is, are there any phone numbers or emails I can start contacting to check if my phone has been dropped inside one of these red mailposts?

[POSTMAN]

Impossible, sorry but it's gone.