My wife lost a lot (>100K) and they told her if she could find some qualifying activity in the past 18 months that was not claimed, they would reinstate the points.

She said she didn't receive an email about the forthcoming expiration, QF said they sent it, and this didn't get any sympathy or traction.

Note what og said, and if your Jetstar fare was eligible for points (big if) then claim it. What you were saving the points for isn't relevant.