Swapping is the oldest trick in the book, street peddlers were doing it with jewelry and watches all the time swapping real one for fakes and sometimes even stealing your wallet in the process
![Cheesy](https://bitcointalk.org/Smileys/default/cheesy.gif)
Do you know any of their names? If you were in a hotel lobby they should be video footage from the cameras.
If you want to get your money back go to the police, tell them to get footage from the hotel, describe those guys and the car they were in and of course tell them the value of coins you were exchanging. If they get caught you'll help all their future victims, because they won't stop with this scam, they'll keep going.
How much did you lose?