Take a look at the order form by editing it under [Packages] -> [Order Forms] and see if you have a checkbox checked for "Require Manual Review and Approval of All Orders". If so, all orders placed on the order form will not be created until you manually approve them for activation.
To manually approve an order, you must have the Orders widget installed, which is available under [billing] -> [Overview]. If you do not see an Orders section when you go to that page, you need to add it to the page by clicking "Manage Widgets" on the left. A pop-up will appear. Drag the "Order System" box to the left side of the pop-up, then close it. The page will refresh and the Orders widget will appear on the page. A table listing will show all orders. A green check icon indicates the order was approved, and a red X icon indicates it has not been approved.
To approve an order, click the checkbox next to the order in the table listing. At the bottom of the table, to the right, an option will appear called "Mark as:" which will allow you to mark the checked orders as a different status (Accepted, Fraud, or Canceled). Setting it to "Accepted" and clicking "Update Orders" will mark the checked order as approved. Once it is approved, the service will be provisioned automatically when 1) the invoice for that service is paid and 2) when the cron runs to provision paid pending services.