RCA getting help on route from another RCA results in half pay?

Forgive my ignorance, Im writing this on behalf of another person who is an RCA and apparently just discovered they have been significantly shorted on their pay. Scenario: RCA has an 8 hour route and the PM sends them help at the end of their route, about an hour of work is handed over. The RCA is paid 50% of the route and the helper is paid the other 50% of the route, even though they were only there for an hour. The RCA was under the impression their time would be put on a green card, and they would be paid hourly but unfortunately that has not been the case. This scenario has been happening to all the RCA's in the office several times a week for many months. What can be done at this point? Backtracking and grieving each particular day without having the records in hand seems like an impossible task. Anyone have this happen to you? What did you do?