We flew from to and Guadalajara June 10 -16, 2017. On return flight, obtained boarding passes on line on flight Y4 977 and at the time paid for 2 small bags to be checked with a visa credit card, name on card: Charles Hall. upon arrival at the airport, not only the service was terrible, the attendants were not very nice. After waiting in a very long line and upon arrival to drop off the luggage, the clerk told us that we had not paid to check in the luggage. We told them that we had paid on line for two pieces of luggage. They asked us for a receipt, and because we did not have the receipt, they did not want to admit that we had paid online. Finally, because we were afraid to lose our flight, we just went ahead and paid again, this time with a visa card in the name of Carmen Stevens. If you want to check this item, our confirmation code was: MFEF3B. We would very much like Volaris to investigate this issue and credit us for the double payment. The names of passengers is: Charles Hall and Maria del Carmen Stevens.