there'll charge me a zloty just to make a withdrawal ((( they will also deduct 15zl for failing to top up account with 1000zl)
That surely must have been in the terms and conditions of the particular bank account you opened? Did no-one point that out to you?
Does anyone know of a bank
If no-one is forthcoming with any recommendations, you can always check out terms and conditions of accounts with each individual bank. A quick search found the fees and commissions charged by your own bank for all their different accounts:-
and here is the same for Alior for example :-
It might be a bit of a pain to go through all the Polish banks' charges, but the fees charged seem to be pretty clear, and will give you a good idea of whether a particular bank account is right for you or not.