If you are a prepaid customer, you must purchase credit before you can place orders.

To purchase credits, after you have login, click on the "Pre-paid credit" link on the Catalog block, click the Add to cart button for the top-up option you want, update the cart with the amount of credit you want (1 Qty = $1) and then click Checkout to complete the purchase. By default, the administrator will need to approve your purchase before the credit is applied to the customer's account.

By default, there is only one top-up option to choose from, that is 1 Qty = $1 credit. The administrator can edit/create other top-up options such as $100 credit for $80 dollars for each quantity sold.