How to Deactivate Your SIM Card If it Is Blocked
- 1). Call the customer service line for your service provider. This number can be found in your phone or from the service provider's website.
- 2). Select the option to speak with a customer service representative.
- 3). Inform the rep that you would like to deactivate your SIM card. You can ask that the SIM card be suspended for a period of time or deactivated completely. If you deactivate the card completely, you will have to pay any outstanding balance on the account.
Source...