A so called premium product with no durability

I have had a Siemens IQ700 washing machine for just over 5 years. During this time I had to replace the tub (R5775), and it has broken down again. After sending it in to an official BSH repair center the machine was deemed unrepairable, but with no visible wear and tear (and I was given a letter to such).

I have had an "upgrade" offer from Siemens which amounts to paying 80% of what I can get a new machine for online.

Surely this is not the kind of quality that one can expect from a premium product like Siemens?

Surely Siemsn cant expect me to pay 80% of a new machine every 5 years?

I have tried to escalate this to your complaints department, but they dont even answer their phones. What must I do, bar going onto social media to get a response?