unhappy with service

Hi

I have a problem with the service plan i have with Hyundai Staria. My STaria has done 4000km since the last service and the service indicator only came up now for the next service. Now i am being told that i should taken the car in for a service 7 months ago even though the car didnt pop up a message. Now apparently it was written in the service book and previous receipt that the car must be serviced in August. No one looks at the previous invoice and service books, thats why the car has an indicator. Now they refuse to pay for the service. This is unacceptable. The vehicle has a built in service indicator for a reason and should be used as such