The worse customer services delivery

Our company has bought x3 Kia bakkies which is used everyday on the road and needs regular services. I've been trying to book our bakkies in for the last 3 months at Kia Motors & Parts Tokia Cnr Main & Keysers Road and have been emailing and calling KIA trying to find out which milage they must also come in for services. To date no one has called or emailed me back regarding my questions, which is very frustrating as they are quick to tell you that the bakkie is out of its maintenance plan and we have to pay cash. I'm really Disappointed in the customer services they display, very bad customer service delivery.