Lost my mobile last night,
Just got another sim (same number)on an old phone.
On my lost phone i was permanently logged in to AB FB gmail etc
trying to change passwords on accounts at the mo.
But on FB after trying to change password it says that
ill be signed in on all devices including my lost phone.
Not what you asked but could be helpful. is it an android and are you with Google/Gmail? If so check Google find my device. It MAY be on there. If so you can remotely lock it and even factory reset it.
Erasing device would take it back to factory settings, as if it had just come out of the box. It won't erase anything on the memory card, though, if you've put one in.
I would lock the phone, change my passwords and keep trying to 'locate/find device'.