It sounds like a term that should be found in Strine, and I swear it was in a Strine dictionary my grandmother had. Only this site seems to agree that “Jeet jet?” is Strine and not just Atlantic coast US.
There were other contractions, too, such as:
“egg nishner” (air conditioner),
“G’dye, myte” (Good day, mate),
“Strine” (Australian),
“Emma Chizzit (How much is it?)
“Wyne chevva cold share” (Why don’t you have a cold shower)
“Rye-Wye” (railway, also Railway, a sub-dialect of Strine spoken by trainmen)
“Kanivan airman pickle semmitch, pleez?” (Can I have a ham and pickle sandwich, please?)
In Strine a lot of things are shortened, such as arvo (afternoon), barbie (barbeque), servo (service station), mozzie (mosquito), sunnies (sunglasses), brekky (breakfast), footy (football), pressie (present/gift), Brissie (Brisbane), Tassie (Tasmania), Aussie or Ozzy (Australia), uni (University), chockie (chocolate), bickie (biscuit), rego (car registration), journo (journalist) and trackies (track suits).
But names tend to get longer, as in Tommo (Tom), Johnno (John), Jacko (Jack), and Davo (Dave).