How does this airline stay afloat; they're hopeless!

We've been trying to cancel a flight booking for days now. We've tried the website (opened our booking and tried to cancel it there but came to a dead end), tried on-line chatting to someone but it said they were busy (we waited over half an hour to get through this way but gave up in the end); tried phoning them and waited for 3/4 of an hour to no avail; tried emailing them but the messages failed.
WHAT SORT OF AIRLINE IS THIS? THEIR CUSTOMER SERVICE IS ATROCIOUS!
WE'LL NEVER BOOK A FLIGHT WITH JETSTAR AGAIN!
YOU'VE GOT TO EXPERIENCE IT TO BELIEVE THAT AN AIRLINE LIKE THIS CAN OPERATE IN A DEVELOPED COUNTRY!

UPDATE 09/07/20 - I tried the chat option again today and got through. THEY HAVE NOW ORGANISED A REFUND.

Domestic
Australia-Sydney
Australia-Melbourne - Tullamarine