Contract Pet Sitter to Pet Sitting Company? What right should I expect, if any?

Okay, I've seen lots of questions about people wanting to start petsitting businesses. I contract visits for a high-end established business, but I'm feeling a bit used. I'm agreeable (OK, a people pleaser) and she's very hot tempered-goes through people like kleenex. I've worked for her for about 2 years with no increase in $, $8 per 1/2 hr. visit, My commute time and gas of course not paid. One day I spent over $6.50 in gas. She acts like I'm on a pager. making requests for same-day visits, for ex. I spent 30 years in the advertising world--we had RUSH rates for stuff like this. People should pay more for the inconvenience. Not sure if I have any options here as she is a bit....odd? She fired my closest friend for getting bitten (this friend has 20+ years SOLID animal and animal-hosp experience) & took something like 9 mos to pay the workman's comp. bill. I'm looking elsewhere, but any ideas on my rights NOW?