Read the instructions on the screen whenever something goes wrong.
Contact WoA on Instagram (https://instagram.com/worldofairports/), Facebook (https://facebook.com/worldofairports/) or email to: worldofairportsgames@gmail.com
Contacting them through Instagram is the fastest way since they are most active there, if you don’t have Instagram, you can ask me or a friend to do so…
Just send them a message describing (in short) how and when it happened (like while playing at a airport or when launching the game etc) and send the screenshot. It would help Devs help you quickly.