Did I read that the municipality provides a free pumpout?
Several issues come to mind. Why didn't you use the free service while on the ball? They come right to you.
Salty sams doesn't have taxpayer funding. What they have is maintainence & operating costs. The fewer people who use it, the higher the per use cost becomes. Most people use the free service so their cost per use goes way up. They likely don't want the hassle of the pumpout but grudgingly provide it. You won't be buying pumpouts there again and they're likely happy with that.
The best solution...buy a lectrasan. As someone noted here, FMB just dumped 8 million gallons of untreated sewage. So all your do-good efforts are routinely subverted by 'the man'.