I am no attorney, but I suspect yes, it is legal, unless it
falls under minimum wage guidelines.
This is going be very very hard for you to do, since you
probably feel you are being cheated, but you should:
1) show more enthusiasm about your job, your
employers, etc. (important)
2) never, never, never complain (very important)
3) be over friendly with your supervisors, and fellow
employees, and show interest in their lives and
their problems (most important).
If you take interest in their lives, they will take interest in
yours, but don't force your problems on other people by
complaining ... it is not the way to make friends.
Most employers do not want to lose a good employee or
a good friend. Eventually you will be rewarded.
Good Luck!
Citizen Brown