What happens with incorrectly addressed correspondence in Poland?

Hi. I live in a small block of apartments and the number of block and apartment is 28 - 5. i was getting correspondence sent to me but i accidentally gave the number 29 - 5. Now there is no building/apartment with that number as the apartment blocks go up in 2's i.e. 28, 30, 32, 34 etc. Does anyone know what happens in that case. There was no return address on the envelope.

Go to the local post office and explain the situation, it is either there or in the local rubbish bin lol

If you have a good postie, your name should be enough. And don't forget the post-code is also used for a reason. I'd say that your mail is probably not in the system yet.