The best option is to send a mail from the game itself.
First go to the main menu of the game, press the wheel in the top right corner to open the settings, tap on Support, and scroll down to "Contact Us."
By submitting your request through the game and your device, we will have additional information that will help troubleshoot your issue or research bugs.
When reporting bugs, please be as specific as possible about what went wrong. If possible, add screenshots and explain the steps you did that resulted in the bug occurring.