Anti theft is activated

Anti theft is activated when replaced a new SIM card. Now I want to reactivate my old SIM card, but when entering the pin code, the device does not turn on, it keeps traying and traying. When I want to reset the device by using the volume button low and On/Off button during 7 sec. I get the start screen, but also immediately the anti theft screen. Can someone help my.

Hi Leopold,

We will work together to sort this out.

To unlock your phone please follow the instructions mentioned in this link: http://avgread.me/1JEloSz .
If that doesnt help, Please click on this link: https://support.avg.com/support_contact_form?l=&retUrl=support_sales.

Select the first option as "YES" and the operating system as "ANDROID"
Fill in the details and click on the option "answer via email".

Once your request is submitted you will be getting the prompt answer via email from our mobile team.