You wrote that your polish friend got a block card too, but he use it in UK, also I think he has transferred money also from UK bank account.... even if he polish, his card was blocked because he used it in another country, or bank or something else.
These cards were for Polish people, so I think they have more than 10 000 cards in a country and if they get their cards block, IMHO: we could find information in Internet, anything. Today I can not find anybody who was in the bank.... NOBODY!!! Can you imagine that? If bank sold more than 100 000 cards and nobody was in the bank? I own more than 20 cards!!!! only I, but I think in Poland there are much more people, who has these cards and no information.

Anyway SPAM SPAM SPAM, I do not think it will help, simpler to have somebody in Poland, who can go to bank. For you: your friend has a family or friend in Poland, you can send cards there and they will authorize your cards, also I think it does not matter how much cards you have. For today I have 3 blocked cards and I am going to Poland in October-November. Anyway I hope that we could find any other possibilities to unlock our cards. I will spend 200-300 euro for this F***ing trip. And this is POLAND.... nothing there. ahhh WHY NOT SPAIN or ITALY?)))