If the government can do it and charge you 5 cents per gallon that's what should happen in a "Free Market"

Except libertarians will run in circles and yell "Goverment intervention!".

What's not good is when the government charges you 15 cents a gallon and a private company can do it for 10 cents but is blocked from doing it because it's not a "Free market".

Example, please? If you will try licensing as example, here's explaination: in terms of wild capitalism(AKA "free market") licensing is allowing to use franchise undrr certain condition.

It's less that the private company is trying to milk you for all your money but "we don't have thousands of taxpayers to subsidize our expenses and inflation exists"

Except it was already clearly stated that they did receive subsidies.