I haved a blackberry pearl and the ball will not turn , how do you fix. Is there a serial number inside the pearl? i think someone switched phones with me.
Using another phone, call your own number and see if your phone rings. If it does, then SIM card wasn't switched. If it doesn't, then you can say that it was switched. Call your provider and let them know that your SIM card has been lost. They will suspend the number until you retrieve it back or they may give you a new SIM with the same old number you have.
As for checking if your phone got switched with someone else's, just check the phone content such as messaging, contacts and photos.