wage dispute

What is the name of your state? Pa. I work as a nurse for an agency. Currently I work at a facility on an evening shift as the only registered nurse and am in charge of 7 employees in addition to having a patient assignment. When I started there, I was informed by the other agency nurses that this facility only paid you staff nurse wages even though the nurse performed charge nurse duties. I mentioned this to my employer and they said they would look in to it. After putting in 1000+ hours at the reg rate, I called my employer and told them I was unwilling to work at the low rate at this facility and requested another assignment. Yesterday, I met my replacement a nurse from the same agency who has been working the days I schedule off. She has been receiving charge nurse wages there performing exactly the same job. She is now going to have my schedule at a rate aprox 8 bucks more an hour. Same employer. Do I have any recourse? Thanks.

None that I can see. As long as you are being paid at least minimum wage, OT as required under the law, and the employer does not make wage rate decisions on the basis of age, race, gender, national origin, etc., they can do whatever they want.