I was allowed to board a flight to Poland. I was supposed to transit to the US through Germany after that. But, I had no Schengen, so the Polish kept me there. I had to lose my ticket and pay for a no stop ticket to the US after that, plus stay over 24 hours in the airport in Poland. Would some one know if I could get reimbursed for my extra travel costs from any entity?
Formally, it would depend on the airline's conditions of carriage and any relevant consumer protection laws in the country where you bought the ticket. But in all likelihood you won't be able to get anything, conditions of carriage usually explicitly specify that passengers are expected to make sure that they meet all relevant visa requirements.
The Polish state certainly will not compensate you or anybody. In fact, they could (and probably will) fine the airline for letting you board the plane in the first place.