Re-iterates my (& few other users here) point that the novelty of large sums of QFF points is wearing off, leaving a very very bad taste. I, too, had booked QF reward seats of partner airlines, had to cancel them because the partner airline kept moving flights around up to the point that I can no longer take the trip and I had to rebook on SQ using VA points. Although, to be fair, in my case, I had also mucked up the trip by booking 2 separate trips.
Regardless, I don't think it's a good idea to book QF reward seats on partner airlines for the foreseeable future. This doesn't mean that the partner airlines are not honouring the reward seats, it is, however, sad to note that QF is, for a variety of reasons, unable to get alternatives for its loyal customers. Understandably, QF can only do so much when the partner airlines cancels/reschedules the flights, but offering a refund as a measure to wash off their responsibilities is not a good colour on an airline using "Spirit of Australia" as it's tagline & selling point.
In this author's humble opinion, QF could have given the OP some options to "somehow" reach their destination with minimum disruption. I'm no specialist in anything airline related, except for being a customer, but I'd think there is always something that can be done by the airline to provide it's customers with a positive experience.
I still fly QF largely and will continue to do so, at least for international sectors. But I'm not above looking to shop elsewhere for the want of better customer experience.