Terrible Customer Service and After Sales Care

I have a flat tire on my vehicle, the warranty requires I fit Audi Approved tires, There are no tires available in the country to complete a set. I can fit 2 tires of one make in front and another make in the rear wheels. I have been verbally advised that this is not a problem by the dealer and Audi "Customer Service". I have requested this confirmation in writing and this was agreed to 6 days ago. It has been agreed to every single day this week that I have called the Customer Service Centre. After losing my temper today I was advised the letter would be sent today.I have still not received what should be a quick email to *** quicker to write than all the details that have been written in this complaint and the information typed into Audi's customer service system each time I call. All I have asked for is an email....in 2022 a written word is sent across the planet in an instant - except if it comes from Audi