Has anyone had experience disputing charges from these guys before?

Last night my return flight was delayed by Air NZ for just over an hour. I had booked to check out of the Auckland Airport car park by 8 o'clock, and it was meant to be around $90 for the duration of my park, which is fairly reasonable (a week). However upon checking my bank account this morning they charged me $188!

Apparently this includes a late fee and is dependent on the signage in the carpark itself - but half the lights in the carpark didn't frikken' work (and I didn't see any signage anyway), there was nothing in my confirmation e-mails about late fees, and the flight being delayed was totally out of my control. I was also under the impression (which I now see is possibly wrong) that the charge was by the day, not hourly or anything.

I have reached out them on Facebook to dispute the amount, as I don't feel this is fair.