Has anybody else experienced a double charge for an upgrade? Back in September, I was offered to upgrade to business class(from economy) for about 700 euros(at no point in time did it show a different price anywhere, even during the checkout flow) for a flight from Barcelona to Toronto during the checking process 24 hours before the flight (which seemed like a good deal), but I was immediately charged around 1400 euros in a single transaction (needless to say, I was the sole traveler). I contacted the credit card company, the physical front desk at the airport and the phone customer service, but they were unable to help me as I didn't have proof the app showed 700 euros charge. I finally got an email from the customer relations team, but they only told me they are unable to refund the charge. I am so confused, is there anything I can do in this case? Feeling scammed by Air Canada