Not working machine poor support regarding exchange by Siemens. Expected much better from them.

I have been a happy Siemens APPLIANCE client for 20 years. 4 months ago I bought a brand new built in coffee machine, the other one stayed behind in the house we sold. I think that was a big mistake. Although that one had already brewed a heck of a lot of coffees for us, a few simple repairs, as in a new grinder, and it worked like a charm again. This machine already started giving us problems after 3 days. They have been trying to fix it 4 times (if not 5) in the 2 months that I have been trying to use it. The supposedly expert repair manager came down from Jo'burg to sort it out. Or so he thought. Got it back on the Friday. Gave same old error on Saturday morning. That left when we filled the water tank again. Gave message to descale, which we had done not even 2 weeks ago. Can't get passed step 6 of 8. Now the lady from head office thinks I don't know how it works. Everything is explained on the display in any case. And it definitely isn't my first built in coffee machine. We already had one 28 years ago. Still waiting for an EXCHANGE of this machine... Doesn't seem to be resolved any time soon. Initially the girl from head office, Aziza, authorized an exchange, now she just keeps delaying the exchange.