Anti-theft locked my Samsung Note

I changed the sim-card and because I had forgotten my code, I followed instructions to change code. That did not work, I continued to get fail messages. So now the device is locked and no action possible. What can I do?

Britt-Eva, Please note that this Community deals mainly with the technical queries regarding AVG Windows products. AVG Android support is provided through email only. Don't know if this will help?.. Have a look @ this article (http://avgclick.me/LockedPhone). Otherwise, Please click on the following link (http://avgclick.me/AVGtechnical) and fill out your details, select as Android then the name of AVG Program that you installed in your mobile and in description please completely explain about your issue and finally click on Email option. Also when filling out your details choose Yes for the Question "Are you currently using any paid/trial AVG products?" even though you may be using the Free version and fill out necessary details and click on Email option. The AVG mobile team will reply back to you via email with a resolution.
AVG Guru