I want to purchase a Miele washing machine from Galaxus. Who is my communication for point if there's a problem with machine? Galaxus or Miele?

Also other suggestions (instead of Galaxus) are welcome in case you had great experience with another retailer

I was advised to not buy trough Fust as they have a poor customer service.

I'd say probably Miele unless it's DOA.

Miele do have very good customer service in my experience.

Manufacturer gives 24 (or more) months of guarantee, regardless where you bought it you contact them.

Some shops in some cases offer ability to bring things to them and then 'forward' them to official service shops for you.

It's Galaxus (the seller) during the warranty period (24 months unless otherwise stipulated).
After that it's Miele or most likely a repair company.

https://www.ch.ch/en/warranty/

Regarding Fust, I heard the same, nevertheless I bought a few things from them because they were just in front of my old apartment. I can't comment on the customer service as all the items still work perfectly after 3 years (including a Miele vacuum).

I have almost all Miele - in 12-years had Miele 2 times (both in last 2-years). Tells the story who you going to call I guess.

Our Miele washing machine broke down a few times in the first 2 years. First time, Called Fust who called Miele. So we then started calling Miele directly. After the 2 year warranty period ended, Fust offered a warranty extension and given the poor record we took it up. We continued to call Miele directly.

Miele told us that the first call should be made to the seller. After that, we are “in their system”.

So next experience is with their combi Steamer which keeps on breaking down. First call to the kitchen installer, who then called Miele. Miele guy came and told us to call him directly next time. Which we did several times until they took the machine back...

Hope your experience with Miele is better than ours...

I have a Miele drier in the basement that came with the apartment... it must be at least 20 years old (probably more). Still going strong. (It was on top of a Miele washer of the same age.. the bearings went last year so had to have it replaced.. what a disgrace! )