When im in Australia, i usually call my fiancee everyday or visa versa... anyway.... in aussie I usually buy the cheap international calling cards... the brand i have always used is called Apple card, or now its called "green card"..with a picture of an apple on it.
If i buy say a 20dollar card from the newsagent.. or even the smaller shops like 7/11 etc.. i can ring a "land line" in indonesia for about 4 hours.. and its usually a good line...you only pay the local cost of call.. or if I called to his mobile phone ...it got me two hours talk time... they will warn you when your credit is running low..
the vouchers come in 10, 20 50 or 100 dollars.
there are heaps of the cheap cards out there, if your not happy with the "green card" try one of the others.
but i have never had any problems.. although one night, we chatted for 3 hours (i was waiting to be cut off) ..and i wasnt "charged" anything.. because there was a problem with their system....not bad...a free 3 hour call to indonesia!!! ha ha ha