The reason I asked if you had a real estate license is that is required in Arizona to be a property manager.
Must an Arizona property management company have a real estate
YES. Key components of property management are considered a real estate activity under existing Arizona real estate licensing laws. A broker's license is required for any person or company who, for compensation, engages in the lease or rental of real estate in Arizona, who offers or lists real estate for rent or lease, who collects rent for the use of real estate or who negotiates the rental or leasing of Arizona real estate. A salesperson working under a broker may engage in such activities.
Arizona is one of the few states having a section in its real estate statute specifically devoted to property management requirements. Arizona law requires that property management agreements contain specific provisions, that all property management accounts are designated as trust accounts, and that records be kept in a certain manner. http://www.allpropertymanagement.com/propertylaw/property-management-law-in-arizona.html
That means that you cannot legally bring suit if you are required to be licensed and you are not.
You would pay taxes only on the amount you are actually paid after the deductions so you cannot take them again.
It appears that they (whoever they are) have changed the rules on you. I would suggest that you sit down and discuss your compensation. If you are licensed, then you could sue them for what they did not pay since they have initially paid you on gross income rather than net income. Most property managers are paid on a percentage of the gross income rather than the net after the deductions. Does that help. Please continue if you need more assistance.