1) If there is no--* contract to the contrary, defining jobs, positions, pay, etc.* no discrimination against a race, sex, religion, the diabled, or those over 40 years in age* no retaliation for having used a protected benefit (e.g. FMLA leave) or filing a protect claim (e.g. for overtime)--then the company gets to define job duties and job pay; it also can demote, transfer, suspend, fire, etc. employees at will. So unless one of the things above, next to the asteriks, applies, the company can make you a cashier's job without a cashier's pay. (If you do have a contract, it is enforceable as to jobs, titles, duties, pay.)2) While a company can usually demote people at will, or reduce their salaries or wages, that is not retroactive; they don't need to give back money earned while they were at a higher rate of pay.