Help! Accidentally left Sandbox mode on with PayPal standard

I accidentally left the Sandbox mode on with PayPal standard.

An order came through but the money didnt go to the account.

When I click the order from Sales>>Orders and go though it using the Continue button I cannot complete it. At stage 5: Totals I get and error saying Payment Method Required even though PayPal is selected. Also the Shipping Method drop down is blanked out.

Is there anyway I can process the order to completion?

Many thanks in advance!

I would contact the customer explaining the situation. They should easily be able to confirm no funds were transferred through their account. Manually request payment through Paypal (invoice or whatnot). Once it's received change the order status to complete.