Proving someone intentionally changed your hours as opposed to a mistake or software bug is not the police's job. It quite literally is a civil crime and belongs in civil court, not criminal. I don't even think most police are trained in civil laws. (Atleast, not in my state?)
Catching someone who takes money out of a cash register is their job. That's textbook theft, a criminal activity.
I hate cops as much as the next guy, possibly more, but that just doesn't seem like their area
FWIW, the government is still (supposedly) working to resolve your issue...your tax dollars are still at work. Judge, Public Defender, blah blah blah....It's just not the job of a first responder