Carry on bag taken then lost because 2kg over weight

So going from Hobart to Sydney on the 29th Dec. Checked in the good old fashioned style at the check in desk and spoke to a check in girl. All went smooth and no questions. Even got an exit isle at no extra charge which surprised me for a budget airline.

So started to board and got asked to check my carry on baggage. I had 1 9kg wheelie bag and a small back pack with my laptop. I have done 100's of flights this way and never been questioned. So they weighed my wheelie bag and said it was 2kg over weight and I would have to put in the hold. I Explained they should have told me this at check in as I had spare room in my check on and could have easily meet the requirements. As I had just finished the Sydney Hobart yacht race and hadn't had much sleep in a few days plus never been that tightly scrutinized on my carry on I didn't even think to check.
So As I didn't really need anything in that bag for the flight I agreed and they added it to a pile of at least a dozen others in the same situation.
So get to Sydney and bag doesn't turn up. Go to baggage services and get told because it was only 20 min before the flight was due to leave there wasn't enough time to load on board so will be on the next flight at 10:45 am the next morning. My problem is I was flying to China at 8:15am that morning so no chance of picking up. There was a cue of people in the same situation.

So asked them to forward to Qingdao which they said they "should" be able to do. So get an email when I arrived in Qingdao to say my back is ready to pick up in Sydney. Reply and tell them the same story again. Get a reply saying "Dont Stress" here are the flight numbers you bag will be on back to Qingdao. So the Airline they said and the flight code didn't match. It had to transfer in Shanghai and the flight they gave were in and out of different airports. Then the internal flight from Shanghai didn't even exist on the day they said. Went to the airport on the off chance it might arrive and off course got told what I already new about the flights.

So emailed, no reply, Emailed the next day no reply. So call and get told the bag is still in Sydney they think. Waiting to hear back.

So yes I was over the limit for carry on so my fault. But going on the industry norms I have never had a problem with that amount of carry on before. If they are going to be that particular about the rules then they have to make that clear at check in so you have an option to correct. To take bags from people at boarding then not put them on the same flight is totally unacceptable in my book.

The amount of hassle this has caused for me, Jetstar and now other airlines to get my bag half way around the world back to me for the sake of 2kg when my total baggage amount was under my limit is just insane.

Might not help but makes me feel better having told my story.

Mark