Use the website to change flights NOT the call centre

I booked a flight and had to change it which was my own fault - annoying but fair enough, they do warn you the cheap fares aren't changeable. I did a direct bank transfer to avoid credit card fees then my wife told me about ten minutes later that the dates didn't work.

Tip #1, Jetstar in NZ banks with ASB, I'm with ASB too unfortunately which meant the transfer went through immediately. I rang the bank to see if they could cancel the transfer - they couldn't, but you might have better luck with other banks.

Tip #2, Pay by bank transfer, but wait three days before you pay just in case any changes come up - in which case you can just not pay and won't lose any money.

So anyway, rang them and was told couldn't do anything until the bank transfer had been assigned, but the guy said they could be changed for around $75 plus any fair difference.

We rescheduled the trip, so I checked new flights online and they were cheaper - $310 vs $330 I paid last week. So I rang today to make the change, expecting to pay $75, and the lady tells me it's going to be $295! Only $15 cheaper than starting fresh?!?
So the breakdown was that the change fee isn't $75, it's $85, and it's per leg, not the whole trip - ah ok, I see what you did there. So what about the remaining $125? Apparently this was "fare differences".
What the...?
As the new flights were cheaper, how does that work? Well apparently their system says my original flights cost $455, I just got a really good discount deal online and "saved" $125. I'm not even sure if that bit is legal, as that's just pulling a figure out of thin air. Nowhere did I ever see the "real" flight cost that their system was showing.

Anyway, so I figure it's still cheaper, so may as well go ahead, then she tells me I can only pay by card, and yes there will be a card fee, and yes the whole thing will cost more than just getting the new flights.

Tip #3, hang up and call your wife (which I did)

Tip #4, go online, put your booking ref and email in and change the flight on there (which she did)

The change fee was only $50 per flight (yes it was in NZD), and one flight cost a bit more than the current online price for some reason (no idea why, a refresh of the front-end website showed it was still available at the same rate as before). Total cost to change was about $155.

$485 return ($330 original + $155 change fees) is still a good price from Akl to Melb, and I'll probably still use DeathStar again in the future, but I completely fail to see why the call centre staff can't use the same booking engine as the website uses. Are the inflated fees and prices to cover the cost of the call centre itself?? Crazy.

Hope any of this helps someone else.