Poor service at William Hunt Pretoria West

William Hunt Pretoria is the dealership for former GM motors for Chevrolet. I bought my Trailblazer there hence preferred to take it back to the dealership for mechanical problems. I took my car on 24 March 2022 and the was diagnosed same day and I given a quote within a short space of time of R29,140.51 for Diesel High Pressure Pump of which I was told that the car will be ready in three days. Furthermore, I was told to make deposit of 50% for them to start working on the car. Instead I paid 60% so that the balance becomes easy for me when the car is ready. Till today i have not receive my car. After feeling the pressure as I was threatening to collect the car, on 29/04/2022 I received a whatsapp message telling me that the part has arrived they will immediately starts working on the car which at first I was told that it's few hours job to put the pump. To my surprise till to date no progress of my car and I am tired using UBER and public transport. Kindly help me either my car to be fixed soonest else they release my car with the part as I paid I would look for assistance elsewhere thank you