Hi Ben,
I was in a similar situation a few years back. I did testing but ultimately I only did General Maths, not 2-unit (NSW name). I was told the same story and they suggested I go to TAFE and do something at a 2-unit equivalent. I spoke to a few people at TAFE and got the course approved by recruiting. It was a statement of attainment in maths and science. I did the initial maths course and physics, then moved onto the advanced ones. Sorry I don't have the subject names, i've forgotten. I believe the statement is being phased out though and a new course being introduced. I didn't finish the course because I moved out of town for uni. I'm now finishing up this year and need to do a maths course again and was told about
Aero Physics in Brisbane. Its a lot more expensive than TAFE ($1600, TAFE is all of about $180 haha) but it is only 4 weeks long whereas TAFE will set you back about 6 months. Speak to Steve, the guy running it. It's apparently ADF approved, however I'd contact recruiting. Basically, search for courses that sound right and seek approval. The issue with the bridging courses is that sometimes there is no mark/certificate given (which ADF usually need) and most don't cover the curriculum necessary. As I said though, just look and ask questions. One thing I will say is that you don't have to go and do the whole HSC course which is a bonus! PM me if you want information on courses I've found.