Hello wise ones

I'm 2 months into my DONE4, and have developed a medical problem necessitating a return to Australia for treatment. Travel insurnce will hopefully provide me with a separate ticket to get home. Because of this I have to abandon some of the sectors I was due to fly in South America to return home, but want to keep the remaining Oceania and Asia sectors.

Can I get a refund for the unused sectors?

The itinerary is SIN - HKG - CDG - MAD - LPB (all sectors from here, where I am now...) - LIM - IPC - SYD - BNE (... to here will be unused) - NOU - BNE - HKG - XIY - HKG - SIN

So essentially I am skipping 4 sectors and would like them refunded, is that possible?