Changing Pay Rate

I am writing this for my wife. She has been having payroll problems since last March 2000. Her pay was decreased with no explanation. She contacted her supervisor and they notified the payroll department on this. They acknowledge that there was an error and that they were researching it. This took months. In their research they found out that my wife was missing a raise from the prior year. My wife has kept in contact with them on this issue every payday through here supervisor. Her supervisor assured her that
she has forwarded all her requests on. About two to three weeks ago, my wife was informed by her supervisor that her pay rate would be adjusted within the next two cycles and that she would get retro for what she has missed.
Two cycles passed and no changed. She informed her supervisor and she told my wife to contact the payroll department directly. My wife called the head of payroll/hr and was informed that this issue had to be take to the board and it should be fixed by February 1st with retro pay.

I guess my question is, can an employer be this irresponsible? Also are they obliged to pay retro on back pay due to their error? Is there any course of action that she can take if February 1st comes and goes with no change?

I know that I have explained my wife's situation but she knows that she is not the only one. She believes that her case is the worst. They have had pay rate problems since the accountant retired several years ago. The employees
receive little to no help from payroll/hr and no support from management.

Any help on this matter would be appreciated.

Thank you,

Wait and see. If no change, contact your state's wage & hour division.