Sometimes (very rarely) your top up won’t go straight through to your meter. In that case you would have to manually top up using the in-home display. It’s really easy.
To access your manual top up press account tab on the main menu screen, select gas or electricity (depending which fuel you want to top up), followed by payment. Type in the ‘vend ‘code you received when topping up in store, online or via text message (you can see it on every receipt) in the payment box.