If you want to start from scratch, simply reinstall the game. You will see the popup offering the old account ― just choose 'No' and the old progress will be deleted.

 

 If you want to completely remove your account from the game, please, do the following steps:

1. Launch the game, go to Settings → Help & Support → Tap on the Chat icon in the right-upper corner to contact Support.
2. Fill up the "Enter your message" field with the following information to prove that you're the real owner of the account:
   1. Your full in-game ID (can be found in the settings)
   2. The model of the device that you used to create the account
   3. The approximate date you created the account (month and year)
   4. Purchase information (GPAs for Google or screenshots of the receipts for Apple)

 You can also contact us at bulletecho@zeptolab.com and provide the information requested above.
 
 Please note that by deleting your account you will not be able to restore it anymore.