I traveled to MEX from Toronto with Aereomexico, because I wanted specific seats, I paid for them when I booked on their website, they had the seats available so I was sure to paid for them. At the airport while documenting they gave me other seats. I asked Aereomexico to refund the money (I did all the email- customer service thing) but they said it out of their control because "emergency exit assignment is subject to airport availability", They don't want to pay. How can I get the refund back.