if I LOST my iPhone...
If I lost my phone and didn't have insurance, I would spend DAYS calling it. I would TEXT it. I would call the places I'd been. I'd call my carrier. I'd talk to Apple. I might (but only might) call the police. But I would make an effort to find it. From the OPs comments, although I'm not sure that refusing to tell the police is right, they're only obliged to go so far to find the owner. If the owner isn't apparently making any real attempt to find the phone, why should the OP make any more attempt to find the owner?
And maybe the owner has insurance? If I had insurance on an iPhone and believed that I'd dropped it, I actually wouldn't want it back, because I'd fear that it was scratched/smashed, would look horrible and wouldn't be reparable. I'd call the insurance company and make a claim, and call the carrier and cancel the SIM card. A brand new (or at least refurbished) replacement would arrive, I'd restore it from a backup, and would be very happy!
In fact, when my partner DID lose her phone, I DID spend a lot of time phoning and texting it, and after a few days a refuse collector found it, switched it on, called me and returned it. If I'd not wanted it, I wouldn't have bothered trying to find it.
Anyway, from the lack of recent comments from the OP, they've either got completely hacked off with being insulted, or it was never real in the first place but they've wound a few people up as intended, or they've found the owner and can't be bothered to tell us, or they've decided to keep it and be damned...
Tiptopp