Breach of employment contract

LOCATION: Arizona

Background: I work in health-care, and is a benefitted FT employee (72 hours). Recently as of April 2026, my boss is canceling full time employees so the we (the area in which we work) are only getting 48 hours per pay period, unless we want to use PTO. If we are regularly not getting our hours and they are violating our employment contract by not guaranteeing our hours, how should we deal with this?