I had to change the date of a flight, and wanted todo it on line. I checked the price of the seat on the website and it was the same as i had originally paid, so went ahead changing the date as only would have to pay an extra £20, however the balance to pay was 30 euros more than it should have been. Gave thomas cook a ring, they agreed it was a mistake and just charged me £20. SO if you think you are being overcharged on the internet, give em a call, or email they will ring you back even if you are in turkey.