Not returning calls, this year and last year

This is my first Hyundai vehicle and the service from your dealership in Diep River is appalling. I phoned twice this week to book the vehicle in for its 45k km service, but no one answers the phone at bookings. The reception took down my number on two different days that I called and till today no one has got back to me. A few months ago when I brought my car in for its 30k km the exact same thing happened and I actually had to drive to the dealership to book the car in. Fortunately, I stay close to the dealership.