Sixt complaint: Dreadful service

Re Gatfield SIXT res number 9919339704 and rental agreement number CNSA1255770RA1

I booked a car to picked up at Cairns Airport for June 12th. Unfortunately, the train from Brisbane ran late and I arrived a few minutes after the pickup counter had closed at 5:30. The only counter of five others in the terminal had closed. I was not contacted by phone or email or any message left at the counter. I had to take a taxi to Palm Cove at a cost of $75 and then a return on the following day of another $75. By phone that following day I was told they could give me another car instead of my original vehicle but at an increased price of $1121.50 instead of the original price of 1031.22. A higher price and having to lose the previous days hire. At the time of the pickup that Saturday 13th June there were no apologies given or even an interest shown in the difficulties I had experienced.
I am very dissatisfied with what has happened and would like you to respond this very unfortunate problem and request that you address my financial loses.