In Reply to: next to the Bintang supermarket posted by lenny on Wednesday, 31. August 2011 at 13:19 Bali Time:
Please keep in mind that the free credit that comes with the sim is very small, just enough to get started, so just because you ran out after one call doesn't mean you got ripped off.
Most Sims come with about rp5000 credit which is good for about 5-10 minute call or maybe 10 local sms.
All Sims have a number you can call to check your balance, for example, Simpati is *888#
So, when you buy your Sim, have the vendor show you how to check the balance and do that before you pay.
Also, the total price for a new Sim should be rp10-15K and that should include 5K initial credit. Before leaving shop, buy an extra 50K credit (will cost 51K usually), and check the balance before you pay.
They can't rip you off if you know what you are doing.