Changed flights, lost baggage

We were booked to fly from Denpasar to Melbourne (QF268), then Wellington (QF037), on 20/21 April. On 20 April we arrived at Denpasar airport at about 9pm to check in for our 11:50pm flight. The check-in agent told us that our booking had changed: we were actually booked to fly to Sydney rather than Melbourne, and we were not now booked to fly to Wellington at all. After some discussion, we persuaded the check in agent to add a flight to Wellington, so we end up at home as we had originally booked and paid for.

We were not given a printed copy of our new itinerary, so we had to write one out on a spare piece of paper. Trying to be sure of the details, we had a long discussion with the Jetstar ticketing agent, who did not know the difference between am and pm. We were very confused as to the times we would be travelling; we were not 100% sure of how long we would have in Sydney between flights as the agent did not understand the difference between am and pm. She told us that we would be arriving in Sydney at 7am, leaving at 9pm and arriving in Wellington at 2am, and also that we would be arriving in Sydney at 7pm, leaving at 9pm and arriving at 2pm. She assured us that our bags would be checked through to Wellington, but told us that we would need to exit the terminal and re-check in in Sydney as she couldn't issue us with a boarding pass for our second flight.

At this point, I glanced at the clock, and saw it was 9:56pm. She had told us our flight left at 10:11pm, and I quickly confirmed this with her verbally. We had to run through the terminal in panic, jumping queues left and right, in order to pay the departure tax, and get through 3 layers of security and border control, all in under 15 minutes. When we arrived at the gate, it turned out that our flight did not leave at 10:11pm, but at 11:10pm. This is a clear error by the Jetstar staff member, and the huge amount of stress this caused was completely avoidable. We made it onto the flight with no other problems.

On our arrival in Sydney, we checked at the transfer desk, and found that we did not actually need to exit security and re-check in for our second flight as we had been told. However, as we checked in, it transpired that the Jetstar ticketing agent in Denpasar had entered the wrong code on our baggage tags. The second flight she booked the bags on, QF37, flies from Melbourne to Wellington; we were in Sydney, having been booked (by her!) on QF 47. This meant a further long discussion with the very helpful Qantas ground staff, who eventually assured us all was well and our luggage (which was still checked in somewhere) would make it to Wellington with us.

We flew to Wellington without further problems. However, our bags did not make it. That was 40 hours ago, and we have been without most of our clothes, medication, toiletries and souvenirs since we arrived back. Air NZ baggage services is unable to tell us where our bags are, or whether they will turn up at all.

We hold Jetstar directly responsible for these problems. We can provide documentation including our original itinerary, a screenshot of the booking as it currently stands (the latest online version shows us flying from Denpasar to Melbourne, then Sydney to Wellington, then Melbourne to Wellington), and the original baggage receipts showing the incorrect flight number.

Could Jetstar please explain:

a) why our booking was changed without notification
b) why our new booking had us finishing in Sydney, when the original booking had us flying home to Wellington
c) why we were booked on a flight to Sydney, when our online booking still shows us flying to Wellington via Melbourne
d) how a Jetstar agent does not have a sufficient grasp of English to be able to clearly inform us of our flight details (we are not discriminating here, we are both experienced English teachers)
e) how a Jetstar agent can check baggage through on the wrong flights
f) where our bags are
g) how Jetstar will compensate us for our missing baggage, the extra expenses we have incurred replacing items we needed immediately on arrival in Wellington (toiletries, medication), and the major stress this has caused us?

PS we have already submitted a complaint.

Indonesia-Denpasar (Bali)
New Zealand-Wellington