score:3
It sounds like your phone is SIM-locked:
https://en.m.wikipedia.org/wiki/SIM_lock
This is imposed by the operator you bought the phone from, and has nothing to do with Poland. Contact your home operator and see if they can unlock it for you. This is usually a paid service.
Upvote:1
It sounds like your phone is Blocked in Poland ie reported as lost or stolen:
This has nothing to do with your provider, your phone(s) might work without any problems in other countries. If your phone(s) was/were SIM-Locked you would get a different message before loading the home screen, something like the this
I am afraid you'll need to get a mobile broadband or a new phone