Flightsite charges you for failed bookings

I just attempted to book a flight on the website.<br> I got an error message that the flight is no longer available although I completed the form within the 10 mins (counter visible on the page). This itself is shameful and a bad customer experience but this is not it!<br> They charged me a fee of 149! This is shameful. I did not read the terms, but its totally bad and unacceptable.<br> Am I paying for a failed transaction and why? <br> Please refund me as I believe this is totally uncalled for and unfair consumer practises. I mean, seriously - its an online transaction!