Or do i need to pick it up from police station somewhere?
As I understand it, they should pass the licence to the embassy, who will then pass it back to ether you or the DVLA. You only have a driving ban in Poland, not elsewhere in the EU, so you should be able to simply retrieve your licence somehow.
I'd contact the British Embassy in Warsaw and ask them how it's dealt with. Either way, you can simply apply for a new licence from the DVLA - just don't drive in Poland until your ban is up.