In Reply to: no, you can't posted by stormy on Thursday, 19. March 2015 at 09:16 Bali Time:
The Checkin staff will reject you unless you have a ticket OUT of Indonesia.
One way aroind this issue, is to buy a cheap AA Ticket OUT of Indonesia.
If you wait for an AA sale, you can buy a ticket from Medan to KL or Bandung to KL for a few dollars.
Last week, I bought a ticket from DPS to MEL for RP 400,000. Adding credit card fees, food and checked in luggage brought the ptice up to Rp 894,000.
If you so not use your AA Ticket, you have very little chance if getting a refund.