Bosch car service bad service

Took my vehicle at Bosch for diagnostic n repairs in 18 April 2023, I did not hear from Bosch regarding the diagnosis I had to follow them around all the time by calling and they kept on promising to call but will never receive a call from them. My vehicle was then taken to Bmw by them without informing me it has been at Bmw from may till to this day have not got my vehicle they keep saying they will get parts to give to Bmw then promise me to call me but I have not received any call ever since from Bosch car Boksburg, I am really dissatisfied and disappointed it’s been three months without my vehicle. The unprofessionalism I’ve received it’s uncalled for, I feel undermined really they don’t care at all