I recall landing in Bali after midnight a couple of years back with only AUS$s on me and finding that the money changers were just closing up so I was unable to get any Rp. Almost ended up being scammed by a porter that I told I had no money to pay him. He took me to a money changer's window that was still open where he spoke to the teller in Indonesian, the teller then immediately closing her window and puting the closed sign up. I only had AUS$50 & 100's on me. He then offered that for AUS$50 he would give me 100,000 Rp (Half the going x-change rate) and carry my bag also! Luckily we had a transfer organised and didn't need cash. He still carried my bag and became quite annoyed when I gave him all the change in my pocket, approx. 85c in coin. He said many indo words that I didn't understand and my driver laughed a lot.... I still wonder what was said.
Does anyone know if the tellers are now open in the early hours of the morning?