List of your mistakes:
When her friend came to tell you she won't meet with, you should move your ass and ask her directly what happened and if you can meet her a bit later because you're leaving Poland soon and care about having next conversation with her.
Another thing is:
Unfortunately this is the only # I have. I feel asking for her number would have put her on the spot more than asking her out for the evening, since it's easier to make an excuse about the evening than it is to come up with a reason not to give a phone number.
OMG! You SHOULD ask her for #. The first thing! Input? WTF. No girl would feel insulted if guy they like ask for that. Well, there are some dumb bitches who will pretend they are so shy and innocent but they are not worth asking.. :P
and she just accepted so she didn't hurt my feelings.
many polish girls do that, even Ive done it a couple of times...
haha, great. Next time when guy will ask you for fuck go and do that ... you can't hurt his feelings, can you?