Tax/hecs dept question

Good evening everyone, so earlier in the year they announced that they where going to lower the indexation rate for the 23/24 financial year for everyone's hecs/help depts and also lower last years indexation by almost 50% and that extra money taken would reflect as a refund this year. Well my question is that I was lucky enough to be able to pay off my remaining dept around Christmas time so I won't be charged any indexation rate for this financial year and that was reflected on my tax return however there was no mention at all about getting a refund on last year's as I technically didn't have a dept to add it back on to, would that $1000 of extra indexation just appear when they finalise my return on their end or do you think it's gone for good. Thanks everyone