Your complaint is with the retailer, not the manufacturer.
Fairly recently Miele revamped their website and their customer service system, and communications are awful or non-existent. From being Which's supplier of the year on a regular basis, at the last survey they're top of the complained-about list.
I called emailed them about a website problem not letting me register my oven, and they telephoned to explain, very apologetically, about the problems, and they'd registered my oven as I gave them the details required. I got the impression the lady I spoke to was even more frustrated than I was as she was dealing with it every day.
My new house (a new build) had five Zanussi appliances fitted by the builder, the oven, hob, dishwasher, fridge/freezer and cooker hood, and they're all crap. So far I've replaced the oven and dishwasher with Miele because of my experience with my Miele vacuum cleaners (the first vc lasted 20 years) and washing machine. The fridge/freezer is next on the list to be replaced by a bigger freezer and a smaller fridge. Miele is my first choice, Bosch second. I have equally good experiences with Bosch products.
But for a faulty product supplied, it's the retailer's responsibility.