My blackberry z3 is blocked how do i fix it - Blackberry Cell Phones

Blackberry is most secure company in world. you can't unlock any blackberry device without secure authentication. or provide needed information,
you must enter your registered email and password and blackberry id to blackberry phone and then you can use that as per needed,
and either you can fully format blackberry phone to re use and completely factory reset after erase each and all data and you need to provide another blackberry id .

Call your service provider.