Go to D-tac or one two call shop and they will stop the use of your Sim card and give you your number back. This is well known.
But did you know they can disable the phone?
You must give them the phones serial number though.
So make a note of it right now!
You can get your serial number up on the screen if you put in -
Star-pound-0-6-pound I am told. Don't know how you punch in pound?
Anyone know?