If your phone is stolen most likely you lost all contacts, pictures, videos, songs, etc. IF YOU kept them on the phone. If you kept them on a 'cloud' you will be able to access them as you establish new phone and service.
If you kept somewhere IMEI of your phone you should report it immediately as stolen so nobody can use it. They can still use your physical SIM unless you get new SIM quickly and transfer number to new SIM. I believe you can even borrow friend's phone just to do phone number transfer from stolen SIM to new SIM.
You do not have to close PM account. Just transfer SIM number from stolen to new SIM. Then deal with rendering stolen phone useless...
