On the right side of the summary you will find your account balance and your maximum allowed debit with us. If you have more debit than this then you account will be placed on hold until payment is made.
Here is also a link that allows you to make payment and clear the balance on your account. You will have the option here of clearing your account balance or just making a onetime payment. Please enter the amount that you wish to pay and then click on the proceed link. If you enter a higher amount than the balance on your account then this will show as a positive credit on your account.
On the following page you can choose if you with to make payment using Paypal or Google Checkout after choosing one of these two option then you will be directed to the payment gateway to complete the payment.