IF you are unable to get any bookings at all on your OWE (something that bears checking again) then one possibility is the pass sold on lan.com, which last time I looked made it possible to go to IPC for a lot less than the normal fare. Are you flexible on your mid Sept dates? I'll take a look at what's available. Keep in mind, however, that mid September is VERY high season in Chile, and that is, perhaps, the reason for the non availability.