Be aware of the service charge. Before you book the flight, click on "price breakdown". Otherwise it is easy to miss, unlike the credit card fee, which is shown in a box you have to click to proceed.
I was confused when i simultaneously received a flight confirmation and a flight denial due to a credit card issue. I called the help centre to make sure the flight was actually booked. The wait time on the phone drove me almost insane and made me incredibly rude to the service person. Which i feel bad about in hindsight.
When i had a question about the cost breakdown, i wrote via email. They surprisingly answered right away, although it took a few emails to get the information straight.