I just find out that they change my sim card

Please follow the below steps to track the device using Anti-theft website:

1) Login to https://www.avgmobilation.com using AVG MyAccount.
2) Now, you can select the device which you want to know the information.
3) You can use the lock, locate and wipe option through AVG Anti-theft website.

NOTE: For Anti-Theft features to be working, the following conditions has to be met.
1. Active data connection on your device.
2. Your device should be turned ON and it should not be formatted.
3. Device should be displayed under Mobilation website, we can help you with re-registration if not listed.

Hope this will help you. If you have any concern, please feel free to contact us at anytime.

Hello, Art. We are sorry to hear that, your mobile device was stolen.

Please be informed that, your mobile can be located using the AVG Anti-theft feature noted that if the mobile is already registered under the https://www.avgmobilation.com website. Please be informed that it is not possible to find the phone number for the SIM that is inserted on your phone. To locate your mobile you can use SMS commands too (http://support.avg.com/SupportArticleView?urlname=AVG-Antivirus-for-Android-Anti-Theft-Commands) but the SIM has been changed and it is not applicable to use SMS command.

Hello, Art. We are sorry to hear that, your mobile device was stolen.

Please be informed that, your mobile can be located using the AVG Anti-theft feature noted that if the mobile is already registered under the https://www.avgmobilation.com website. Please be informed that it is not possible to find the phone number for the SIM that is inserted on your phone. To locate your mobile you can use SMS commands too (http://support.avg.com/SupportArticleView?urlname=AVG-Antivirus-for-Android-Anti-Theft-Commands) but the SIM has been changed and it is not applicable to use SMS command.

How can I find out who stold it or take a pic off who stold my sim card