What country was your destination? Saying "between" doesn't disclose which country you landed in. Also, what country are you located in? The process differs between NZ and Australia, also it is quite possible another pax picked up your notebook and then handed it in to the airport lost and found, not to the airline.

Contact phone numbers for JQ are at http://www.jetstar.com/au/en/contact-us#BaggageServices and differ by country.

But if JQ doesn't have it, then definitely try the arrival airport lost and found, also email customs there and maybe even try city police lost and found, in case it was turned in outside of the airport (e.g. try bus, train, etc.). I'd say chances are slim if the airline doesn't have it and they are normally very good about lost & found.