I booked a flight two days before departure. When I arrived at the airport, I couldn't board the plane until I payed again. I was told the airline (GOL in Brazil) has not received the payment yet. They forced me to pay another time, although I had already payed with my credit card - I could even show them as it was already deducted from my account (online banking).
So far, after 12 days, they could not solve the issue, the customer service is not getting back to me as promised. I have not received any reimbursement.
GOL is annoying!