@Ed101 If you went to ijji.com and then to "add g-coin", every option they provide allow for you to be able to get 50 gcoin. Your best bet, is probably to buy an ultimate game card or wallie card. If you have a credit card, then you can just buy 50 g-coin from there website. Other options include:
Paysafecard and more.
Just go here: https://billing.ijji.com/payment/paymentprocess.nhn