Is it your first time "purchasing" FG?
* Please note that your first purchase will not be instant. Your payment will need to be manually validated for your first purchase, but after that you will be able to buy FG instantly and automatically at any point in the future by using the Purchase Gold page.
Taken from
http://forums.d2jsp.org/info.php?p=1It can take anywere from 5 mins - a week for it to be validated (my first purchase took 6 days to recieve my FG & Star)