How to find out mobile phone number for iPhone 3GS? - 1

I just bought an iPhone on a 24 month contract.

It came in the box with
-Instructions
-iPhone
-Simcard
-EarPhones
-Wall Charger
-USB iPhone Cable

but i actually don't know, the mobile phone number?

How do i find it out?

The iPhone is on a contract with Vodafone.

Why doesn't my iPhone 5 have personal hotspot? - 1

Personal hotspot has disappeared. It's not there when I open Settings.
It's not in Settings<General<Cellular either. My carrier doesn't require paying for tethering to work and everything about my iPhone is identical to my friends iPhone. All the settings, iOS versions, all that stuff.
Why doesn't my iPhone have personal hotspot? It just doesn't appear and, apparently, nobody else has had this problem, because when I search on Google it doesn't appear. Everyone says "Settings<General<Cellular" but it just isn't there. It just says "Cellular network settings" which takes me to the APN where the DATA settings of my carrier are included. No signs of "Personal hotspot" anywhere. Why is that?

EBay seller shipped broken item and deleted their account?

I bought an "iPhone" on EBay from a seller claiming it worked perfectly fine for $400 and the seller shipped but the iCloud is locked. The seller failed to mention this and now iim out $400 and they deleted their account. What do I do and will they be stopped?