Very unhappy customer

Terrible customer service. They notified me to say car is ready. I then made arrangements to leave work early and have a colleague drop me at home as I have no other means of transport, for them to collect me at home. Once at home the service advisor then calls to say they have just taken the car for a test drive and the problem is still there. Im now left stranded without any mode of transport for the weekend. I moved over to Mercedes from audi expecting better but now think that was a wrong move. This is not the first time this has happened to me. I expected much better from the Mercedes brand.