Share your experience!
Call blocking on Z2
Hello @SuB01 , welcome to the forum! 
I'm afraid that there is no inbuilt feature in your device to block calls. You can however add a unwanted number to your contact list and send incoming calls from that number directly to your voice mail service. To do that, follow the instructions below:
There are also a variety of call blocking applications available in Play Store, you might find something really great there.
Have a nice day!
Thanks for that. I've now installed a call blocker app!