Indigo Airlines — Booking error leading to being charged twice

I went to book a flight and an error page at the end of the process came up saying it did not work so I used another card to book the flight and once again it said it did not work. After I made the two booking later or it came through saying it worked and took two booking off me and now I can’t find a way to get my money back for the companies own mistakes with the misleading error page! After that I could cancel one of the bookings and I was charged over £80 I also never got any email confirmation not any confirmation number if wasn’t the card text message.