I am a law school graduate. What I offer is mere information, not to be construed as forming an attorney client relationship.
You need to give us the state in which this is happening.
But here is a general answer pulled from the employment law section of freeadvice.com:
I WORK PART-TIME FOR A LARGE, NATIONALLY RECOGNIZED COMPANY AND THEY STIFFED ME ON MY PAYCHECK: THE HOURS I WORKED WERE CUT IN HALF. MY BOSS TOLD ME THEY DIDN'T HAVE ENOUGH MONEY TO PAY ME, BUT WOULD MAKE IT UP THE NEXT WEEK. WHAT ARE MY RIGHTS?
Your boss may only mean he doesn't have enough money in his store or department's budget to pay you this week and he'll pay you next. But it is a crime not to pay workers. So if you are not paid the following week (double-check your pay stub and hours), report the company to the Department of Labor in your state.