Earning Status Credits Without Flying?

[serfty]

The problem is you have already purchased points within the last 12 months.

Unfortunately not, which is most annoying. I already have purchased
5000 points and it will not let me make the award. I called up QANTAS
U.S. and they explained it was due to "not enough earned" points even
though its well above 85% which is why I need to earn the remaining
points. I think its a route by route rule. LAX-SYD/MEL is a very popular
route for QF so I can see why they don't want to give seats away
without a fight!

Anyway, thanks for your help. I'm going to try to get a AA flight
that gives me the loyalty bonus.

Regards.

There is your problem (highlighted); Here are the rules regarding Top-up points (as linked to by simongr). Check clause 18.1(e). This is causing your issue:

18. Top-up Points

18.1 If Members do not have sufficient Points to redeem a particular Award Flight, they may purchase additional Points towards that Award Flight at the rates specified by Qantas from time to time, subject to the following:
(a) the purchased Points may only be credited to that Member's account;
(b) the Points may be purchased only to redeem a specific Award Flight;
(c) each purchase must be for a minimum of 500 Points and a maximum of 20,000 Points, and in such blocks of Points as Qantas may specify from time to time;
(d) the number of Points purchased must not exceed 15% of the number of Points required for that Award Flight, rounded up to the closest multiple of 500 points;
(e) each Member may purchase additional Points only once in each twelve consecutive month period; and
(f) once Points have been purchased, they cannot be refunded.