If you purchased the wrong tickets, you can rebook them by exchanging the amount for a voucher code of the same price. The voucher can then be used for the purchase of your new desired tickets.
To rebook, simply SIGN IN to your user account at the top right corner, then click on “My tickets”. There you will find the ticket you wish to change. Click on “More” and you’ll see the option to rebook the ticket on your own by obtaining a voucher code of the same value.
Please note that the option to rebook is available up to 24 hours before departure.