Our billing system identifies any extra payments and they get automatically refunded to your credit balance. You may view your credit balance on your client web admin page.
After logging in, click on the upper right "Notification" in gray text, to display the credit balance.
This extra payment may have occurred because your PayPal account subscription keeps sending payments.
PayPal subscriptions are handled by PayPal and thus need to be cancelled on the PayPal site.
Click on the following link to learn how to cancel your subscription on PayPal's site: http://www.wikihow.com/Cancel-a-PayPal-Subscription