bad service

I purchased a car in january around the 17th, only got the number plates and disc on the 26th of February an I had to fetch them, no one told me that they were ready for collection and the sales man told me that a radio will be fitted in the car on the 3rd of March later on that day they say they are investigating the issue of the radio. On the 5th I went back to the dealership to hear what the issue was and the guy by the name of Michael said he will get back to me till this day he hasnt, whenever I call they take a mesaage at reception but no one gets back to me.