Pathetic Service by Mercedes SA and Mercedes Pinetown!

I bought my A200 on the 22nd of February 2020. My vehicle is still under warranty and the service plan in place. I unfortunately hit a pothole on the 13th of Aug 2020 which punctured by run flat Bridgestone tyre. I have been told by Mercedes Pinetown that they cannot find a tyre since then. Now they want to replace both back tyres with different tyres. How the heck does Mercedes Benz not make provision for instances like this - why is there no stock? Then on top of it all they have been sitting with my vehicle for 5 days and blatantly refuse to provide me with a loan car. This is the first Mercedes I bought and I cannot wait to get rid of it. The service is absolutely shocking and pathetic!