Poor Service

In January 2015 I took my car for a service and on the 09 February I was travelling from Bisho then I saw an orange light on the dashboard, the following day the 10th I took it back to Hyundai and I was told there was something wrong with engine. They had to place an order for two parts the senser and other part I can't remember. It was on the 10th February. A week later I called the manager from the service department and he said he's still waiting for the parts, as soon as he get them he will contact me. I called again in march and I was told he was on leave. A week later I called and the guy said he will come back to until today nothing has been done, there's no communication , they do not call. Everytime I take my car to this company there's always problem because this is not the first incident. Please help.