Don’t know if the law allows it in your state, but in mine they can’t fill more than 80%. I also tell them when to come fill up my tanks - once in Spring and again in the Fall.
I’m trying to find out if that is the law here, but having no luck. If it’s not a law, then I won’t complain because I’m not a fan of more laws. I’ll just go with a new company where I can negotiate the contract better as another poster suggested.