Bloom - where in QLD are you from?
Tabata training sets are 4mins in duration, but you can do a number of sets. Ordinarily, a class that uses Tabata format will include a 10min warm up, 20 min tabata (with 1 min rest between sets, so 25min total), then 10 min cool down and stretch. So 45min in total.

I use Tabata a lot lately in my CageFit classes, Warrior and Bootcamp sessions, and even in PT sessions with my PT clients. I love it. But to drop body fat and firm up, weights training is much more effective. Building muscle will keep you burning more fat for longer each day - cardio training burns fat only while you're working out, and only if you're in an optimal heart rate zone. Unfortunately, restricting calories AND doing cardio training will only cause muscle atrophy (muscle wastage).

I lost over 60kg, then put on almost 20kg with cancer treatments. Lost 8kg in 11days, then the weight loss on the scales stopped.... but my clean eating and exercise plan kept my body fat % going down further and further. Measurements are such a great way to determine how effective your program is working... not scales. I have lost 80cms off my body in just over a month - yet the scales haven't changed.

..... so my long story IS for a reason....
What i'm trying to say is - throw those scales away. Measure your body instead. Enjoy your healthy eating and continue exercising because I'm sure you are moving mountains, even on the days you feel like you're banging your head against them!