Dishonest cheap airlines who try to rob every $$ from you

So this morning I travelled to Sydney from Melbourne with family of 12 including 4 kids. As advertised each person allowed to carry 7 kg of luggage. However at the gates, a lazy, rude and unprofessional gate keeper randomly pick 3 of us and send us back to pay extra luggage. They have another guy at the back to process the payment of extra luggage. This guy just make random decision to charge 2 of us $195 for extra luggage fee. Each of us carry 12kg of luggage which we explain that it is our kids luggage as it is impossible to get the kids to carry even 5kg of item themselves. They don't bother to listen to us and force us to pay the fee saying that if we argue, they'll leave us and we won't able to fly. The guy blamed me for not processing the luggage as a group which is incorrect. He also said that he only work here and if other staff sent us back to him, his job is to charge us. I explained that we come in a group and the guy who sent us back processed us together. He told me to submit complaint to customer service (which I already suspect will only waste my time). We can confirm that all of us are not exceeding the baggage allowance and it even fall below it. For a record, we also come early before the gate even opened. I tried to talk to the guy but he just play dumb and told us to go away.

So I tried to complaint and explain to customer service online... And as expected, I chat with a human robot who only able to follow protocol which clearly designed to care, listen and treat customer fairly.

Well... In the end of the day only monkey take peanuts and you get what you pay. However in this case the monkey is not only give you bad customer service but also rob you. To me, its not about the $ but I hate this kind of dodgy treatment. I actually should anticipate this kind of cheap tricks considering Jetstar is Qantas subsidiaries which recently complained for being racist to afro-american artist will.am.

Domestic
Australia-Melbourne - Tullamarine
Australia-Sydney