[Ombudsman]

You can try to sue the airline but you'll find ity very difficult to find an attorney who will take your case on contingency so you'll probably be oaying for all legal fees uyoursel up front. The reason I say this is although the airline made an error in allowing you to board in Prague the onus is upon the traveler to secure all necessary documents and visas prior to travel. I'm sorry to say this is one battle you're probably not going to win. Additiomally, it was your choice to fly to Dubai where you were again refused entry. Which airline did you fly there? You never mentioned suing them. However, I digress. My point being that if an airline does carry a passenger without proper visas/docs for transit or entry at the destination, they are obligated to return you to your point of origin at no additional expense to you in addition to possibly facing a fine. I'm sorry if this is not what you want to hear but my advice is to chalk it up to experience and move on.