Reading your post I can see the clash of cultures.
The seller wants you to have cash when you go to the notary public for transfer of title.
You don't want to take cash because you believe you are going to get ripped off.
Maybe no-one has explained to you before a notarial act in Poland is sacred territory and must always be dealt with in cleared funds, showing him your credit card he was really trusting you.A credit card is not cleared funds, you could have cancelled the transaction with your card issuer immediately after the notarial act.
You must have bought one to many timeshare ...
We were expecting to have a few viewings lined up but they had other ideas, they wanted us to buy some apartments they owned instead.
Below is a company in Krakow they may be able to find you property, there is a decent chap there by the name of Alex he is good and know the market.