Is there a law stateting that you can not leave the premise on your paid 15 min. break?:confused:

No, but neither is there any law that says the employer cannot prohibit you from staying on the premises during your rest break. After all, rest periods of 15 minutes such as you are describing are paid time.

Bottom line, it is entirely up to the employer whether you can or cannot leave the premises during your break. The law does not address it.