(Is there a way to add funds from another country if you don't have a bank account in Poland? Why is it so hard?
Try this I just did it (from the US) and it worked: mobilerecharge.
I received a text from T-Mobile Tak Tak right away that my account has been recharged even though the website says "Order Status Pending".
My phone works, hope it works for you also!
Select Poland, choose provider, add your credit card info and Polish phone number and you're set to go. I'm currently using both my US and Polish number (in the US) and they work fine.