My recent Bill and the 3 previous show a GST amount that is greater than 10% of the sum of the goods and services provided by AGL. The total pre GST takes into account usage, supply, discounts and the feed in from my solar. Total cost $296.39 - GST $ 38.82 BUT this should be $29.64!!However I fed in $91.83 of energy from my Solar system which is GST exempt COULD this be the difference between the actual GST charged and what the law states I should be charged?? Guys please if you have a solar s ...