Skoda Auto - Faulty car sold

I have sent the car * time for the same problem and this time they say they had to get the part from Germany. Once they got the part and fixed it they now say that another part has gone and they need to fix that and get that part from Germany. They have had my car for over * and half months in the workshop. They have given me a standby car not even worth **% of my original car. It’s a test drive model and I get stopped on the way to work almost everyday cause it’s a test drive model and the car has no insurance. I have voice recordings as prof of everything I have spoken to them about on the phone.