I cannot unlock anti theft

I cannot unlock avg anti theft. I don't know what happen  to my cell phone, Note 4. I did not change SIM card but avg showed "This device was locked due to SIM change". AVG mail (noreply mail) to informed me but with no solution or any troubleshooting way. Please help.
Hello Phoompong,
Sorry to know that you have issues with Anti theft application.
Please contact our Mobile support through the following link http://bit.ly/1EC8H4H .
Please fill out your details, select as android then the name of AVG Program that you installed in your mobile and in description explain about your issue completely and finally click on Email option.
Our AVG mobile team will reply back to you via email with a resolution.
Thank you.

Hello Phoompong,
Sorry to know that you have issues with Anti theft application.
Please contact our Mobile support through the following link http://bit.ly/1EC8H4H .
Please fill out your details, select as android then the name of AVG Program that you installed in your mobile and in description explain about your issue completely and finally click on Email option.
Our AVG mobile team will reply back to you via email with a resolution.
Thank you.

Phoompong, Please note that this Community deals mainly with the technical queries regarding AVG Windows products. AVG Android support is provided through email only. 
AVG Guru