Failure to give Feedback From Sales

In February 2015 I took my car in for it's 96000 km service at Jeep Sandton it was picked up that the radio is faulty and that a new radio has been ordered for me and that I would be contacted to fit it in once it arrives. I never heard anything I called the dealer twice to follow up and the lady at switchboard took my numbers and promised someone will call me back on both those occasions but no one ever did. I finally called again and spoke to the service consultant who told me I can't be helped because my car is out of the maintenance plan I asked to speak to manager I was sent from pillar to post with no assistance. I called the head office and a gentleman called Jason M said he'll follow the matter up and come back to me he never gave me feedback promised from the manager, I called head office again looking for him and he was off work that day I spoke to someone else who also promised to follow the matter up and come back to me but never did. To me that is terrible service and *************. I phone and wait for minutes on the line to get assistance but nothing done.