When you say paid less than 3000PLN in taxes, do you not mean earned less than 3000PLN (ie income, wages) ? Because I think that's the approximate annual limit before a person gets taxed in PL (in the UK it's GBP10 tys. approx.).
Of course you're right. That's tax free income limit, not tax amount as I said.
when all the Poles went to the UK and got legal jobs and paid tax on their UK employment, did they pay that tax to the UK tax office or the Poland tax office for the first 6 months of the tax year of their stay in the UK?
Here it says that people who live in UK and come working for short term to Poland are obliged to pay taxes in Poland only from work performed in Poland. So they don't have to pay for example taxes from interests in Poland, but UK. It must be symmetrical for Poles coming for short term to UK.
Osoby mające miejsce zamieszkania w innym kraju podlegają natomiast opodatkowaniu w Polsce tylko w zakresie dochodów z pracy wykonywanej na terytorium RP na podstawie stosunku służbowego lub stosunku pracy. Przepisy te stosuje się z uwzględnieniem umów o unikaniu podwójnego opodatkowania.
Actually I would like somebody who knows to answer how can I get back tax from my investments (lokata) in Polish banks if I am tax resident in Germany? Tax is commissioned automatically in Poland, but according to the above law I should pay it in Germany, not Poland.
And about the poster question, weather money can be claimed back. I think that I've heard that I can claim money back in Germany only if I am already tax resident here. But probably somebody told me wrong.