My two sons both have Samsung gusto, and I refill them at the same time each month. One of them shows a balance of zero, even though there is 20.00 on the account according to the website. So it appears the balance is not updating on the display on one of the phones. Is there any way to make it update? It is awfully inconvenient to have to keep checking online for the balance when its supposed to be displayed on the screen.