Brisbane and metropolitan petrol price cycle, seems like a rip off!!

In south east Queensland, that being the gold coast, Logan, the Redlands, Ipswich and of course, all suburbs north to the sunny coast and Brisbane, all these areas have a strange petrol price cycle going on.
I am told most of our state is like this in some way!

This started around 15 to 20 years ago and each year seems to get worse, by worse i mean the gap between the highs and lows with our fuel price gets larger!!
When this all first started it was said it was due to world fuel prices, we don't make much of our own fuel here any more, i think it is made in Singapore then shipped here.
They say its why it is this way, but when the world price of oil goes up, the next day or in a couple of days the service stations usually put the price of fuel up, i don't think the dearer fuel gets here from over seas that fast, lol.
The government wont act on this rip off due to taxes, there is of course GST and fuel excise tax that equates to 42cents per litre of purchased fuel, so there is no help from the government on this!!
The prices drop then suddenly up they go then slowly drop over some weeks, until its as low as they all will go, then they all go up again!!

This was the fuel price at the pumps of many fuel stations as of the 11/11/2020, they do vary, but our area can be a slightly expensive area, being Brisbane's bayside


This the price at the same servo on the 12/11/2020