Appalling service from Audi

I am completely appalled by the service of this so called Executive company. My A3 gearbox has a malfunction and the car is still under warranty, it will take Audi 21 days to get the part from Germany. They have refused to offer me a courtesy car to use in the meantime and now have to go a month without a car whilst still paying for it. I have had 2 A4s before this one and my 2nd A4 also had the same gearbox malfunction, obviously it’s something wrong with their useless gearboxes. Am planning to change the A3 in the next 4 mnths and it will definitely not be for an Audi. How the heck am I supposed to commute to work without a car?