Cutting hours after not taking salary offer

My wife has worked at this resturant for 5 yrs. She started out out at $5 hr. With in less than a year she was up to $9hr due to her hard work ethic.
The resturant was sold and she was hired on at $10hr. She has worked for these owners for 4-1/2yrs. She has shown them 100% dedication. In 4-1/2 yrs she has only missed a total of 5 or 6 days due to sickness. Her on avg hrs was anywhere from 35 to 38hrs a week. There where times where she work 21+ days straight due to some one quiting, or some one not shown up, leaving the kitchen staff in a pinch. Its vital to keep the kitchen open because its also a bar and food sales have to be a certain percentage for liquior licenseing requirments.
Her last raise was 2 yrs ago, and is now at $11 hr.
She recently went to them and asked for a raise and explained to them that "hey I need X amount every two weeks to help pay bills."
They offered her $800 every two weeks, with no compensation if asked to work over 40hrs per week.
She told them "no, I need at lest $850 -$900 per two weeks"
Well here is the kicker, they came back and cut her hrs down to 30hrs one week and 36hrs the second and said " I bet you wished you would have taken the $800 now!"
She would have if they would have told her at the time her hours where going to be cut, but they did not say anything about it.
They gave her a .25cent raise.
They keep telling her that her pay is not going backwards. We beg to differ, thats $8000 less a year her income will be.
Is there any hint of retaliation on her employers behalf for not taking the $800 every two week offer?
One owner told her the other day to "stop getting the other kitchen help(only 3 others work in the kitchen) riled up over her situation, that everyone else is happy and they are tired of hearing her complaining."
She does not have to say anything to the others,they see how the owners have been and are treating her.
Its really sad becaues when Bill and Joel bought the place they told her....
Quote " the more money we make, the more money you'll make."
Yeah, and its employers like them that bring on the need for Unions.

Thank you for your time and any advise you can give.
Sincerely
Frank J. Collier III