A. Immediately report any unauthorized transaction through the app. Go to the 'Transactions' section, select the transaction in question, and choose 'Report Issue'. Follow the prompts to dispute the transaction. Make sure to document the transaction details for your records.

B. Change your account password and enable two-factor authentication (2FA) if available. This adds an extra layer of security to your account. To change your password, go to 'Settings' > 'Security' > 'Change Password'.