A Customer Service Manager you do not want in your flight in case of an emergency

My husband and I paid for 2extra leg room seat (exit seats) for some comfort on a overnight flight from Bali to Sydney. As we boarded the plane, we realised we were on a standard economy seat (no leg room). It was then explained to us that the plane had 4 exit seats but 6 people had purchased the extra leg room seats and were on board. The other 4 people must have done the check-in before us, hence they got what they paid for. This was not raised with us at check-in. I took the problem to the Customer Service Manager, who was extremely unhelpful and rude. She basically said she couldn't do anything for us, threated to restrain me to a chair (because I asked her if I had to lay down on the floor to get the leg room I paid for), called me a child because I wasn't "working with her" ie surrendering to the no alternative type of statement. Finally after one hour of discussion, I basically said to her that if Jetstar failed to provide me what I paid for, any customer service manager would provide an equivalent or better alternative. She repeated many times it was against the company's policy and procedure to upgrade us to business class. She obviously couldn't handle the situation, which was a quite simple mathematics problem: 6 people but 4 seats = 2 upgrade. She then turned her back to me, walked away, to return 5 minutes later and guided us to 2 exit row seats! Then I realised she had just upgrade 2 of the 4 people who were in the exit seats to business.... not us! It was clear to me that woman's customer service skill set was not only very poor but she made a decision based on her ego, it became personal towards us. I was horrified with that behaviour coming from a manager.... and she would be the woman the passengers would have to follow instructions in case of an emergency???? she is so self-centred that she would be the first one to jump off the plane!!! No need to say, we were so upset for having to argue for one hour and we were then unable to relax and sleep. She could have upgrade any 2 of the 6 people, just didn't have to put us through one hour of horrible argument....