Once again I did receive my card immediately after contacting bernard75 (thanks again!). Until now I can't report of any issues and the card was accepted at all places I tried to use it. The card works as outlined and can easily be loaded using the withdraw function on bitstamp.net
As mentioned in the german subforum, the card balance can also be checked by sending an SMS to a polish service number:
Check the card balance:
1234567890ABCD S
and send to: +48 66 100 2425 (costs depend on your service provider)
or show the card's history with the previous transactions:
1234567890ABCD H
with:
1234567890 being the last 10 numbers of the card's bank account number
and
ABCD being the last 4 numbers of the credit card number