Cell phones are one of the most common items stolen by thieves, and are almost just as easily lost by their users as well. In the event that your cell phone is ever lost or stolen, the first thing you must do is have the phone deactivated. Deactivating the phone makes sure that nobody else can use the phone, and that your plan remains untouched.
Contact your cell phone carrier. You should be able to use their technical support or customer service number. Try to find an actual representative to help you with your deactivation.
Inform the representative that you need to deactivate your phone. Provide the representative with your name, account number and phone number of the phone you want to deactivate. If you have the IMEI number of the phone, provide that as well.
Confirm that you want the phone deactivated. The phone will no longer be able to make calls with your account.